{"id":22608,"date":"2026-08-21T12:08:45","date_gmt":"2026-08-21T12:08:45","guid":{"rendered":"https:\/\/www.sysinfotools.com\/blog\/?p=22608"},"modified":"2026-08-21T12:15:27","modified_gmt":"2026-08-21T12:15:27","slug":"ews-retirement","status":"publish","type":"post","link":"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/","title":{"rendered":"EWS Retirement Enters Its Final Stage: What MigrationWiz Users Should Know"},"content":{"rendered":"<div class=\"block_sum\">\n<p><strong>Introduction:<\/strong> Exchange Web Services (EWS) has supported many Exchange Online migration projects for years. Now, Microsoft is moving into the final phase of EWS retirement. For organizations using MigrationWiz with Exchange Online, this change should not be treated as a future concern. Some configuration work is already required.<\/p>\n<p>Microsoft has introduced <strong>EWSAllowedAppIDs<\/strong>, which allows Microsoft 365 administrators to decide which applications can continue using EWS. If your MigrationWiz project uses EWS and Exchange Online is involved, the required application ID needs to be allowed. In this guide, we will explain what is changing, what MigrationWiz users need to configure, and how to protect mailbox data before starting a migration.<\/p>\n<\/div>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_81 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<div class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/div>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#What_Is_EWS_and_Why_Is_Microsoft_365_EWS_Retirement\" >What Is EWS and Why Is Microsoft 365 EWS Retirement?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#What_Is_EWSAllowedAppIDs\" >What Is EWSAllowedAppIDs?<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#What_MigrationWiz_Users_Need_to_Do\" >What MigrationWiz Users Need to Do<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#Why_the_October_1_2026_Deadline_Matters\" >Why the October 1, 2026 Deadline Matters<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#Allow_Time_for_Microsoft_365_Changes\" >Allow Time for Microsoft 365 Changes<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#Take_a_Backup_Before_Starting_the_Migration\" >Take a Backup Before Starting the Migration<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#Why_You_Should_Test_Before_the_Migration\" >Why You Should Test Before the Migration<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#Final_Words\" >Final Words<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#Frequently_Asked_Questions\" >Frequently Asked Questions<\/a><\/li><\/ul><\/li><\/ul><\/nav><\/div>\n<h2 class=\"main_heading\"><span class=\"ez-toc-section\" id=\"What_Is_EWS_and_Why_Is_Microsoft_365_EWS_Retirement\"><\/span>What Is EWS and Why Is Microsoft 365 EWS Retirement?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Exchange Web Services (EWS) is a Microsoft technology that allows applications to work with Exchange mailbox data. It has been widely used to access emails, calendars, contacts, and other mailbox information.&nbsp;<\/p>\n<p>Microsoft is gradually moving Exchange Online toward newer APIs and technologies. Because of this change, EWS is being retired in stages rather than being switched off all at once.<\/p>\n<p>The final phase brings tighter control over applications that still need EWS access. <a href=\"https:\/\/techcommunity.microsoft.com\/blog\/exchange\/introducing-ewsallowedappids-preparing-for-the-final-phase-of-ews-retirement\/4529471\/replies\/4544317\" target=\"_blank\" rel=\"noopener\"><strong>Microsoft has introduced EWSAllowedAppIDs<\/strong><\/a> to help administrators manage this access. For migration teams, this means EWS settings should now be checked as part of the normal migration preparation process.<\/p>\n<h2 class=\"main_heading\"><span class=\"ez-toc-section\" id=\"What_Is_EWSAllowedAppIDs\"><\/span>What Is EWSAllowedAppIDs?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><strong>EWSAllowedAppIDs<\/strong> is an allow list that Microsoft 365 administrators can use to specify which applications are permitted to access EWS. In simple terms, an administrator can identify an approved application by its Application (client) ID and add that ID to the tenant&#8217;s EWS allow list.<\/p>\n<p>This is crucial to MigrationWiz users because when performing migrations based on EWS, you might require the application ID used in the authentication of Microsoft 365. It also helps give more control to administrators concerning third-party applications trying to access Exchange Online.<\/p>\n<h3 class=\"main_heading\"><span class=\"ez-toc-section\" id=\"What_MigrationWiz_Users_Need_to_Do\"><\/span>What MigrationWiz Users Need to Do<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ol>\n<li aria-level=\"1\"><strong>Set up Modern Authentication fully: <\/strong>Sign in and configure the required Microsoft 365 app needed for migration.<\/li>\n<li aria-level=\"1\"><strong>Find the Application (Client) ID: <\/strong>This is the ID for the registered app used for authentication purposes.<\/li>\n<li aria-level=\"1\"><strong>Add the App ID to EWSAllowedAppIDs<\/strong>: Add the required application ID to the Microsoft 365 tenant&#8217;s EWS allow list.<\/li>\n<li aria-level=\"1\"><strong>Check the configuration<\/strong>: Make sure the correct App ID has been added and there are no typing errors.<\/li>\n<li aria-level=\"1\"><strong>Wait for some time to get it done: <\/strong>It is better to wait and not make changes before migration.<\/li>\n<li aria-level=\"1\"><strong>Test the connection<\/strong>: Run a test before moving the complete set of mailboxes.<\/li>\n<\/ol>\n<h3 class=\"main_heading\"><span class=\"ez-toc-section\" id=\"Why_the_October_1_2026_Deadline_Matters\"><\/span>Why the October 1, 2026 Deadline Matters<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>The October 1, 2026 date is an important point in the Exchange Online EWS retirement timeline. Microsoft is introducing stricter EWS access rules for tenants that continue to have EWS enabled but do not configure the required application allow list.<\/p>\n<p>Once the new behavior applies to a tenant, applications that are not included in the allowed list may no longer be able to use EWS. For this reason, migration teams should not wait until the deadline is close. If a migration is planned for the coming months, EWS configuration should be reviewed during the planning stage.<\/p>\n<p>Microsoft has also been communicating the upcoming changes through the Exchange Team. The earlier article <a href=\"https:\/\/techcommunity.microsoft.com\/blog\/exchange\/exchange-online-ews-your-time-is-almost-up\/4492361\" target=\"_blank\" rel=\"noopener\"><strong>Exchange Online EWS, Your Time is Almost Up<\/strong><\/a> provides additional background on the retirement.<\/p>\n<h2 class=\"main_heading\"><span class=\"ez-toc-section\" id=\"Allow_Time_for_Microsoft_365_Changes\"><\/span>Allow Time for Microsoft 365 Changes<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>One point that migration administrators should keep in mind is that configuration changes may not become active immediately. Therefore, adding an App ID just before a migration is not a good idea. After making the change:<\/p>\n<ul>\n<li aria-level=\"1\">Verify that the App ID is present.<\/li>\n<li aria-level=\"1\">Record the current allow-list configuration.<\/li>\n<li aria-level=\"1\">Give Microsoft 365 enough time to apply the change.<\/li>\n<li aria-level=\"1\">Test the migration connection.<\/li>\n<li aria-level=\"1\">Run a small migration before starting the full project.<\/li>\n<\/ul>\n<h3 class=\"main_heading\"><span class=\"ez-toc-section\" id=\"Take_a_Backup_Before_Starting_the_Migration\"><\/span>Take a Backup Before Starting the Migration<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>EWS configuration is only one part of migration preparation. In addition to that, it would be prudent to maintain a duplicate copy of the relevant mailbox data before undertaking significant modifications to the Microsoft 365 environment. The backup will come in handy in situations where certain items are skipped during the migration process, or the migration process gets stalled halfway.<\/p>\n<p>The <a href=\"https:\/\/www.sysinfotools.com\/office365-backup.php\" target=\"_blank\" rel=\"noopener\"><strong>SysInfo Office 365 Backup Tool<\/strong><\/a> can be considered as part of a pre-migration backup plan. The tool is designed to back up Office 365 mailbox data and save it in formats such as PST, PDF, EML, MBOX, and CSV. It can be useful for:<\/p>\n<ul>\n<li aria-level=\"1\">Support for large Office 365 emails, contacts, and calendars with accuracy.<\/li>\n<li aria-level=\"1\">Features like Remove Duplicate, Date Filter, Attachment handling, and more.<\/li>\n<li aria-level=\"1\">Secure authentication mode using Modern or Admin Impersonation.<\/li>\n<li aria-level=\"1\">Maintains the original email formatting structure and metadata.<\/li>\n<li aria-level=\"1\">Highly compatible with all Windows, Mac, or Linux versions.<\/li>\n<\/ul>\n<div class=\"blog-btn\">\n<ul id=\"db-btn-container\" class=\"nav nav-tabs mt-4\" role=\"tablist\">\n<li class=\"nav-item\"><a id=\"windows-tab\" class=\"nav-link active\" role=\"tab\" href=\"#windows\" data-toggle=\"tab\" aria-controls=\"windows\" aria-selected=\"true\"><i class=\"icon-windows\"><\/i> Windows<\/a><\/li>\n<li class=\"nav-item\"><a id=\"mac-tab\" class=\"nav-link\" role=\"tab\" href=\"#mac\" data-toggle=\"tab\" aria-controls=\"mac\" aria-selected=\"false\"><i class=\"icon-apple\"><\/i> Mac<\/a><\/li>\n<\/ul>\n<div id=\"db-btn-containerContent\" class=\"tab-content my-2\">\n<div id=\"windows\" class=\"tab-pane fade active show\" role=\"tabpanel\" aria-labelledby=\"windows-tab\"><a class=\"sum-d-btn\" href=\"https:\/\/www.sysinfotools.com\/demo-version\/Sysinfo-Office-365-Backup-Tool_win.exe\"><i class=\"icon-windows\"><\/i> Download<\/a> <a class=\"sum-b-btn\" href=\"https:\/\/www.sysinfotools.com\/buynow\/office365-backup.php\" target=\"_blank\" rel=\"noopener\"><i class=\"icon icon-basket\"><\/i> Buy Now<\/a><\/div>\n<div id=\"mac\" class=\"tab-pane fade\" role=\"tabpanel\" aria-labelledby=\"mac-tab\"><a class=\"sum-d-btn\" href=\"https:\/\/www.sysinfotools.com\/demo-version\/Sysinfo-Office-365-Backup-Tool-mac.dmg\"><i class=\"icon-apple\"><\/i> Download<\/a> <a class=\"sum-b-btn\" href=\"https:\/\/www.sysinfotools.com\/buynow\/mac-office365-backup.php\" target=\"_blank\" rel=\"noopener\"><i class=\"icon icon-basket\"><\/i> Buy Now<\/a><\/div>\n<\/div>\n<\/div>\n<h2 class=\"main_heading\"><span class=\"ez-toc-section\" id=\"Why_You_Should_Test_Before_the_Migration\"><\/span>Why You Should Test Before the Migration<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>A full mailbox migration can involve hundreds or thousands of users. Discovering an Exchange Web Services retirement or authentication problem after the migration has started can cause unnecessary delays. A small test migration gives administrators a chance to check:<\/p>\n<ul>\n<li aria-level=\"1\">Microsoft 365 authentication<\/li>\n<li aria-level=\"1\">EWS access<\/li>\n<li aria-level=\"1\">Application permissions<\/li>\n<li aria-level=\"1\">EWSAllowedAppIDs configuration<\/li>\n<li aria-level=\"1\">MigrationWiz endpoint settings<\/li>\n<li aria-level=\"1\">Mailbox access<\/li>\n<li aria-level=\"1\">Folder and message migration<\/li>\n<\/ul>\n<h2 class=\"main_heading\"><span class=\"ez-toc-section\" id=\"Final_Words\"><\/span>Final Words<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Microsoft&#8217;s EWS retirement is an important change for organizations planning Exchange Online migrations with MigrationWiz. The introduction of EWSAllowedAppIDs gives administrators a way to control which applications can continue using EWS during the transition. Before starting a migration, review the tenant&#8217;s EWS settings, complete the required authentication setup, identify the correct Application ID, configure the allow list where required, and test the connection.<\/p>\n<p>It is also sensible to back up important mailbox data before the full migration begins. A separate backup can provide an extra layer of protection if the migration is interrupted or some data needs to be checked later. Most importantly, do not leave EWS preparation until the migration day. Review the environment early, test with a smaller mailbox set, and keep your configuration documented.<\/p>\n<h3 class=\"faq_heading\"><span class=\"ez-toc-section\" id=\"Frequently_Asked_Questions\"><\/span>Frequently Asked Questions<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n<div class=\"schema-faq wp-block-yoast-faq-block\"><div class=\"schema-faq-section\" id=\"faq-question-1787312817286\"><strong class=\"schema-faq-question\">Q1. What should MigrationWiz users do before the EWS retirement deadline?<\/strong> <p class=\"schema-faq-answer\"><strong>Ans. <\/strong>MigrationWiz users should review their Microsoft 365 EWS settings, complete the required Modern Authentication setup, identify the correct Application (Client) ID, and add it to EWSAllowedAppIDs when required. A test migration should also be completed before moving all mailboxes.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1787312819092\"><strong class=\"schema-faq-question\">Q2. How long does it take for EWS configuration changes to take effect?<\/strong> <p class=\"schema-faq-answer\"><strong>Ans. <\/strong>Microsoft 365 configuration changes may take some time to apply. After updating EWSAllowedAppIDs, administrators should allow sufficient time for the change to take effect and then test the connection before starting the migration.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1787312820699\"><strong class=\"schema-faq-question\">Q3. Should I test MigrationWiz before migrating all mailboxes?<\/strong> <p class=\"schema-faq-answer\"><strong>Ans. <\/strong>A small test migration can help confirm that authentication, EWS access, application permissions, mailbox access, and MigrationWiz endpoint settings are working correctly.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1787312821291\"><strong class=\"schema-faq-question\">Q4. What Microsoft 365 data should be checked during a MigrationWiz test?<\/strong> <p class=\"schema-faq-answer\"><strong>Ans. <\/strong>Check important mailbox data such as emails, folders, contacts, calendars, and other items included in the migration plan. This helps identify missing or incorrectly migrated data before the full migration.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1787312821868\"><strong class=\"schema-faq-question\">Q5. Does EWS retirement affect all Microsoft 365 tenants?<\/strong> <p class=\"schema-faq-answer\"><strong>Ans. <\/strong>The impact depends on how EWS is being used in the tenant and which applications require EWS access. Organizations using applications that depend on EWS should review Microsoft&#8217;s retirement requirements and their current tenant configuration.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1787312822436\"><strong class=\"schema-faq-question\">Q6. What happens if the MigrationWiz application is not added to EWSAllowedAppIDs?<\/strong> <p class=\"schema-faq-answer\"><strong>Ans. <\/strong>If EWS access is restricted for the tenant, an application that is not included in the allowed list may be unable to access Exchange Online through EWS. This can prevent or interrupt migration activities that depend on EWS.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1787312823676\"><strong class=\"schema-faq-question\">Q7. Does changing EWSAllowedAppIDs affect existing mailboxes?<\/strong> <p class=\"schema-faq-answer\"><strong>Ans. <\/strong>EWSAllowedAppIDs controls application access to EWS rather than changing mailbox content. However, applications that rely on EWS may be affected if their Application ID is not permitted.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1787312824188\"><strong class=\"schema-faq-question\">Q8. What should I do if MigrationWiz cannot connect after configuring EWSAllowedAppIDs?<\/strong> <p class=\"schema-faq-answer\"><strong>Ans. <\/strong>First, verify that the correct Application (Client) ID was added to the allow list. Then check the authentication method, application permissions, EWS settings, and MigrationWiz endpoint configuration. Running another connection test can help identify the issue.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1787312824844\"><strong class=\"schema-faq-question\">Q9. What are the risks of starting a migration without testing EWS access?<\/strong> <p class=\"schema-faq-answer\"><strong>Ans. <\/strong>Starting without testing can lead to authentication failures, connection problems, incomplete migrations, or unexpected delays. Testing a small number of mailboxes first allows administrators to correct configuration issues before the main migration.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1787312825411\"><strong class=\"schema-faq-question\">Q10. Do you need to have backups for your Microsoft 365 data before the process of migration via MigrationWiz?<\/strong> <p class=\"schema-faq-answer\"><strong>Ans. <\/strong>A backup is not always needed for the migration; however, having a separate backup of your mailbox data is good just in case you want to have another opportunity for recovery.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1787312946461\"><strong class=\"schema-faq-question\">Q11. Why is Modern Authentication necessary for MigrationWiz?<\/strong> <p class=\"schema-faq-answer\"><strong>Ans. <\/strong>Modern Authentication offers a more modern authentication process to access the Microsoft 365 services. Finishing the required authentication process and configuring the application will allow MigrationWiz to gain access to perform the necessary migration.<\/p> <\/div> <\/div>\n\n\n<div class=\"kk-star-ratings kksr-auto kksr-align-left kksr-valign-bottom\"\n    data-payload='{&quot;align&quot;:&quot;left&quot;,&quot;id&quot;:&quot;22608&quot;,&quot;slug&quot;:&quot;default&quot;,&quot;valign&quot;:&quot;bottom&quot;,&quot;ignore&quot;:&quot;&quot;,&quot;reference&quot;:&quot;auto&quot;,&quot;class&quot;:&quot;&quot;,&quot;count&quot;:&quot;0&quot;,&quot;legendonly&quot;:&quot;&quot;,&quot;readonly&quot;:&quot;&quot;,&quot;score&quot;:&quot;0&quot;,&quot;starsonly&quot;:&quot;&quot;,&quot;best&quot;:&quot;5&quot;,&quot;gap&quot;:&quot;5&quot;,&quot;greet&quot;:&quot;Rate this post&quot;,&quot;legend&quot;:&quot;0\\\/5 - (0 votes)&quot;,&quot;size&quot;:&quot;24&quot;,&quot;title&quot;:&quot;EWS Retirement Enters Its Final Stage: What MigrationWiz Users Should Know&quot;,&quot;width&quot;:&quot;0&quot;,&quot;_legend&quot;:&quot;{score}\\\/{best} - ({count} {votes})&quot;,&quot;font_factor&quot;:&quot;1.25&quot;}'>\n            \n<div class=\"kksr-stars\">\n    \n<div class=\"kksr-stars-inactive\">\n            <div class=\"kksr-star\" data-star=\"1\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" data-star=\"2\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" data-star=\"3\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" data-star=\"4\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" data-star=\"5\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n    <\/div>\n    \n<div class=\"kksr-stars-active\" style=\"width: 0px;\">\n            <div class=\"kksr-star\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n    <\/div>\n<\/div>\n                \n\n<div class=\"kksr-legend\" style=\"font-size: 19.2px;\">\n            <span class=\"kksr-muted\">Rate this post<\/span>\n    <\/div>\n    <\/div>\n","protected":false},"excerpt":{"rendered":"<p>Introduction: Exchange Web Services (EWS) has supported many Exchange Online migration projects for years. Now, Microsoft is moving into the<a class=\"read-more ml-1 main-read-more\" href=\"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/\">Read More<\/a><\/p>\n","protected":false},"author":1,"featured_media":22613,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1594],"tags":[],"class_list":["post-22608","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-cloud-backup"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.2 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>EWS Retirement &amp; EWSAllowedAppIDs: MigrationWiz Guide<\/title>\n<meta name=\"description\" content=\"Learn how EWS retirement affects MigrationWiz and how to configure EWSAllowedAppIDs, test access, and protect mailbox data before migration.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, 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With a background in computer science and a passion for writing, I thrive to deliver complex technical content in simple layman terms.","sameAs":["https:\/\/www.sysinfotools.com\/","https:\/\/www.linkedin.com\/in\/simran-bhatia-190169299"],"url":"https:\/\/www.sysinfotools.com\/blog\/author\/admin\/"},{"@type":"Question","@id":"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#faq-question-1787312817286","position":1,"url":"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#faq-question-1787312817286","name":"Q1. What should MigrationWiz users do before the EWS retirement deadline?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"<strong>Ans. <\/strong>MigrationWiz users should review their Microsoft 365 EWS settings, complete the required Modern Authentication setup, identify the correct Application (Client) ID, and add it to EWSAllowedAppIDs when required. A test migration should also be completed before moving all mailboxes.","inLanguage":"en-US"},"inLanguage":"en-US"},{"@type":"Question","@id":"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#faq-question-1787312819092","position":2,"url":"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#faq-question-1787312819092","name":"Q2. How long does it take for EWS configuration changes to take effect?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"<strong>Ans. <\/strong>Microsoft 365 configuration changes may take some time to apply. After updating EWSAllowedAppIDs, administrators should allow sufficient time for the change to take effect and then test the connection before starting the migration.","inLanguage":"en-US"},"inLanguage":"en-US"},{"@type":"Question","@id":"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#faq-question-1787312820699","position":3,"url":"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#faq-question-1787312820699","name":"Q3. Should I test MigrationWiz before migrating all mailboxes?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"<strong>Ans. <\/strong>A small test migration can help confirm that authentication, EWS access, application permissions, mailbox access, and MigrationWiz endpoint settings are working correctly.","inLanguage":"en-US"},"inLanguage":"en-US"},{"@type":"Question","@id":"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#faq-question-1787312821291","position":4,"url":"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#faq-question-1787312821291","name":"Q4. What Microsoft 365 data should be checked during a MigrationWiz test?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"<strong>Ans. <\/strong>Check important mailbox data such as emails, folders, contacts, calendars, and other items included in the migration plan. This helps identify missing or incorrectly migrated data before the full migration.","inLanguage":"en-US"},"inLanguage":"en-US"},{"@type":"Question","@id":"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#faq-question-1787312821868","position":5,"url":"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#faq-question-1787312821868","name":"Q5. Does EWS retirement affect all Microsoft 365 tenants?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"<strong>Ans. <\/strong>The impact depends on how EWS is being used in the tenant and which applications require EWS access. Organizations using applications that depend on EWS should review Microsoft's retirement requirements and their current tenant configuration.","inLanguage":"en-US"},"inLanguage":"en-US"},{"@type":"Question","@id":"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#faq-question-1787312822436","position":6,"url":"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#faq-question-1787312822436","name":"Q6. What happens if the MigrationWiz application is not added to EWSAllowedAppIDs?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"<strong>Ans. <\/strong>If EWS access is restricted for the tenant, an application that is not included in the allowed list may be unable to access Exchange Online through EWS. This can prevent or interrupt migration activities that depend on EWS.","inLanguage":"en-US"},"inLanguage":"en-US"},{"@type":"Question","@id":"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#faq-question-1787312823676","position":7,"url":"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#faq-question-1787312823676","name":"Q7. Does changing EWSAllowedAppIDs affect existing mailboxes?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"<strong>Ans. <\/strong>EWSAllowedAppIDs controls application access to EWS rather than changing mailbox content. However, applications that rely on EWS may be affected if their Application ID is not permitted.","inLanguage":"en-US"},"inLanguage":"en-US"},{"@type":"Question","@id":"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#faq-question-1787312824188","position":8,"url":"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#faq-question-1787312824188","name":"Q8. What should I do if MigrationWiz cannot connect after configuring EWSAllowedAppIDs?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"<strong>Ans. <\/strong>First, verify that the correct Application (Client) ID was added to the allow list. Then check the authentication method, application permissions, EWS settings, and MigrationWiz endpoint configuration. Running another connection test can help identify the issue.","inLanguage":"en-US"},"inLanguage":"en-US"},{"@type":"Question","@id":"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#faq-question-1787312824844","position":9,"url":"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#faq-question-1787312824844","name":"Q9. What are the risks of starting a migration without testing EWS access?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"<strong>Ans. <\/strong>Starting without testing can lead to authentication failures, connection problems, incomplete migrations, or unexpected delays. Testing a small number of mailboxes first allows administrators to correct configuration issues before the main migration.","inLanguage":"en-US"},"inLanguage":"en-US"},{"@type":"Question","@id":"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#faq-question-1787312825411","position":10,"url":"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#faq-question-1787312825411","name":"Q10. Do you need to have backups for your Microsoft 365 data before the process of migration via MigrationWiz?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"<strong>Ans. <\/strong>A backup is not always needed for the migration; however, having a separate backup of your mailbox data is good just in case you want to have another opportunity for recovery.","inLanguage":"en-US"},"inLanguage":"en-US"},{"@type":"Question","@id":"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#faq-question-1787312946461","position":11,"url":"https:\/\/www.sysinfotools.com\/blog\/ews-retirement\/#faq-question-1787312946461","name":"Q11. Why is Modern Authentication necessary for MigrationWiz?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"<strong>Ans. <\/strong>Modern Authentication offers a more modern authentication process to access the Microsoft 365 services. Finishing the required authentication process and configuring the application will allow MigrationWiz to gain access to perform the necessary migration.","inLanguage":"en-US"},"inLanguage":"en-US"}]}},"_links":{"self":[{"href":"https:\/\/www.sysinfotools.com\/blog\/wp-json\/wp\/v2\/posts\/22608","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.sysinfotools.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.sysinfotools.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.sysinfotools.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.sysinfotools.com\/blog\/wp-json\/wp\/v2\/comments?post=22608"}],"version-history":[{"count":6,"href":"https:\/\/www.sysinfotools.com\/blog\/wp-json\/wp\/v2\/posts\/22608\/revisions"}],"predecessor-version":[{"id":22615,"href":"https:\/\/www.sysinfotools.com\/blog\/wp-json\/wp\/v2\/posts\/22608\/revisions\/22615"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.sysinfotools.com\/blog\/wp-json\/wp\/v2\/media\/22613"}],"wp:attachment":[{"href":"https:\/\/www.sysinfotools.com\/blog\/wp-json\/wp\/v2\/media?parent=22608"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.sysinfotools.com\/blog\/wp-json\/wp\/v2\/categories?post=22608"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.sysinfotools.com\/blog\/wp-json\/wp\/v2\/tags?post=22608"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}