AWS WorkMail to Office 365 Migration: The Complete 2027 Guide

• Last updated: 10 April 2026
• Migration
• Editorial Team

For years, Amazon WorkMail served organizations as a dependable managed email solution — secure, scalable, and tightly integrated with AWS infrastructure. That era is ending. AWS has officially confirmed it will shut down Amazon WorkMail permanently on March 31, 2027, making migration no longer optional but essential.

Microsoft 365 — with Exchange Online at its core — is the natural, proven destination for WorkMail customers. This guide walks you through every step: understanding the EOL deadline, choosing the right Microsoft 365 plan, executing a zero-downtime migration, and handling post-cutover configuration. Apps4Rent, a Tier 1 Microsoft Cloud Solution Provider with 25,000+ migrations completed, provides free migration for businesses making the switch through us.

Amazon WorkMail Is Shutting Down — The Critical Deadline

Why Microsoft 365 Is the Best WorkMail Replacement

Microsoft 365 isn’t just a like-for-like email replacement — it’s a complete upgrade that adds the collaboration tools Amazon WorkMail never offered, starting at the same $4/user/month price point.

• Exchange Online – the gold standard in enterprise email, powering 95%+ of Fortune 500 inboxes, now fully cloud-hosted with a 99.9% uptime SLA.
• Outlook desktop app – most WorkMail users already use Outlook; Microsoft 365 makes it native with full Exchange Online integration and no reconfiguration friction.
• Microsoft Teams – fills the collaboration gap WorkMail never addressed: chat, video meetings, channels, and co-authoring in one unified platform.
• Microsoft Copilot AI – AI built directly into Outlook to draft emails, summarize long threads, and surface action items automatically.
• Microsoft Purview compliance – eDiscovery, litigation hold, DLP policies, and audit logs for regulated industries including healthcare, legal, and finance.
• Entra ID (Azure AD) – single sign-on, multi-factor authentication, and Conditional Access policies for organizations already in the Microsoft ecosystem.
• Same starting price – Exchange Online Plan 1 starts at $4/user/month — identical to WorkMail’s pricing, with a dramatically superior feature set.

What Data Can Be Migrated from Amazon WorkMail to Office 365?

• Migrates Successfully

  • Emails — all messages, sent items, drafts, deleted items, and custom folders via IMAP migration batch
  • Calendar events — meetings, recurring appointments, and reminders (via iCalendar export/import)
  • Contacts — personal and shared contacts (via vCard export and Exchange Online import)
  • Folder structures — WorkMail folders map faithfully to Outlook/Exchange Online folder hierarchy
  • Email rules — can be recreated as Outlook rules or Exchange transport rules post-migration

• Requires Manual Reconfiguration

  • Distribution lists — recreated as Microsoft 365 Groups or Exchange distribution groups
  • Shared mailboxes — reconfigured in Exchange Admin Center with appropriate delegate permissions
  • Resource mailboxes — conference rooms and equipment mailboxes need manual recreation
  • Email signatures — set up fresh in Outlook or via Exchange transport rules
  • DNS records — MX, SPF, DKIM, and DMARC all need updating to Microsoft’s servers

Pre-Migration Checklist: Prepare Before You Begin

Poor preparation is the single biggest cause of failed or disruptive migrations. Work through every item below before executing any technical steps.

1. Audit Your WorkMail Environment

   Inventory every mailbox, alias, distribution list, shared mailbox, resource mailbox, and custom domain. Export this as a spreadsheet — it becomes your migration manifest and CSV source file.

2. Choose the Right Microsoft 365 Plan and Purchase Licenses

   Select your plan based on the comparison above. Purchase licenses for all users being migrated through Apps4Rent for the best pricing and bundled migration support.

3. Add and Verify Your Domain in Microsoft 365 Admin Center

   Go to admin.microsoft.com → Settings → Domains. Add your custom domain and complete DNS verification using the TXT record provided. Do not update MX records yet.

4. Create an Admin Role Account in Amazon WorkMail

   Assign admin rights to a migration role account from the Amazon WorkMail console or via Active Directory for WorkMail. This account needs access to all source mailboxes.

5. Confirm IMAP Is Enabled on All WorkMail Accounts

   Verify IMAP access is enabled. Note your WorkMail IMAP server address by region — for example, imap.mail.us-east-1.awsapps.com for US East. Port: 993, Encryption: SSL.

6. Provision All Microsoft 365 User Accounts and Assign Licenses

   Create destination user accounts in Microsoft 365 Admin Center and assign Exchange Online or Microsoft 365 licenses to each one so mailboxes are provisioned and ready before migration starts.

7. Lower DNS TTL Values 48 Hours Before Cutover

   Reduce the TTL on your MX and related DNS records to 300 seconds (5 minutes) at least 48 hours before your planned cutover. This makes DNS propagation near-instant when you flip the switch.

8. Communicate the Migration Schedule to All Users

   Notify users at least two weeks before migration. Tell them what’s changing, what they need to do (reconfigure Outlook, set up MFA), and who to contact for help. Early communication dramatically reduces post-migration support tickets.

Step-by-Step: Migrating from AWS WorkMail to Microsoft 365

Two migration methods work for WorkMail. IMAP Migration (via Microsoft 365 Admin Center) suits most small-to-mid organizations. PowerShell-based batches offer greater control for larger deployments.

Method 1 — IMAP Migration via Exchange Admin Center

Suitable for most organizations under 150 users. Migrates email. Contacts and calendars are handled separately.

Phase 1 — Create Migration Endpoint

• Open Exchange Admin Center (EAC)

  Navigate to admin.microsoft.com → Exchange Admin Center → Migration. Click Migration Endpoints then New

• Select IMAP as the Endpoint Type

  Choose IMAP from the endpoint options. Enter the WorkMail IMAP server: imap.mail.[your-region].awsapps.com · Port 993 · Security SSL.

• Enter Admin Credentials and Test Connection

  Provide the migration role account email and password. Click Next. Microsoft tests the IMAP connection — if it fails, confirm IMAP is enabled in WorkMail settings and credentials are correct.

• Name and Save the Endpoint

  Give it a clear name like WorkMail-IMAP-US-East and save. This endpoint is referenced when creating migration batches in the next phase.

Phase 2 — Create and Run Migration Batches

• Prepare Your CSV Mapping File

  Create a CSV with one column: EmailAddress — one WorkMail address per row. For address remapping, include a second column. Maximum 50,000 rows per batch file.

• Create a New Migration Batch

  In EAC → Migration, click New Migration Batch, select your saved IMAP endpoint, and upload the CSV file. Name the batch and optionally set a start date filter to limit which historical email is included.

• Start the Batch During Off-Peak Hours

  For large mailboxes, choose Manually start later so you can schedule the batch during low-usage periods (weekends or overnight). Click Save then Start at the appropriate time.

• Monitor Progress and Handle Failures

  Track progress in the EAC Migration dashboard. Each mailbox shows status: Syncing, Synced, or Failed. Run Get-MigrationUser -Status Failed in PowerShell to list failures and investigate individually before proceeding to cutover.

Why Choose Apps4Rent for Your WorkMail Migration?

Migrating from Amazon WorkMail to Microsoft 365 is more involved than simply copying emails. DNS changes, shared mailbox setup, Outlook reconfiguration, MFA enforcement, contacts and calendar handling, and user training all need precise coordination. One misconfigured MX record can cause hours of email downtime — and one missed DKIM record can route your legitimate email to recipients’ spam folders.

• Tier 1 Microsoft CSP — highest-tier Microsoft partner status, enabling best-in-class pricing and direct Microsoft escalation paths unavailable to end customers
• Zero downtime cutover — dual-delivery configuration means email flows continuously during migration; MX records only switch after all data is fully verified
• Complete data scope — emails, contacts, calendars, shared mailboxes, distribution lists, resource mailboxes, and folder structures all migrated faithfully
• DNS and email security — MX, SPF, DKIM, and DMARC correctly configured so your migrated domain never lands in spam
• Outlook reconfiguration — we guide every user through desktop and mobile Outlook setup on Microsoft 365, including Autodiscover verification
• User training and onboarding — Teams orientation and Microsoft 365 onboarding sessions so your team is productive from day one
• 24/7/365 post-migration support — real people, not bots, available by phone, chat, and email after migration completes
• Fixed-price packages — clear, transparent pricing agreed before migration begins; no surprise invoices mid-project

Amazon WorkMail vs Microsoft 365 — Feature Comparison

Frequently Asked Questions

The most important questions WorkMail customers are asking about the 2027 shutdown and migration to Microsoft 365.

1. When exactly is Amazon WorkMail shutting down — and what happens to my data?

   Amazon WorkMail reaches end of support on March 31, 2027. After this date, the WorkMail console and all WorkMail resources become permanently inaccessible — including every email, contact, calendar event, and attachment stored in the platform. AWS has announced no post-shutdown data recovery option.

   WorkMail also stops accepting new customers from April 30, 2026. Existing accounts remain functional until the hard shutdown date, but should not be relied upon as data becomes unrecoverable afterward. We strongly recommend beginning migration planning now — large organizations may need 3–6 months to migrate safely.

2. What is the cheapest Microsoft 365 plan that replaces Amazon WorkMail?

   Exchange Online Plan 1 at $4/user/month is the most direct, cost-equivalent replacement for Amazon WorkMail. It provides a 50 GB Exchange Online mailbox, Outlook Web App, calendar and contacts sync, anti-spam and anti-malware protection, mobile device sync via ActiveSync, and a 99.9% uptime SLA — all for the same monthly cost as WorkMail.

   For just $2 more per user per month, Microsoft 365 Business Basic at $6/user/month adds Microsoft Teams (chat + video meetings), 1 TB OneDrive storage, and web versions of Word, Excel, and PowerPoint — making it the most popular choice for WorkMail customers seeking a complete upgrade.

3. Will my email address and domain change after migrating to Microsoft 365?

   No — your email addresses remain exactly the same. Your custom domain (e.g., @yourcompany.com) moves with you. The migration involves adding your domain to Microsoft 365, verifying domain ownership, migrating your mailbox data, and then updating your MX records to route new email to Exchange Online. Users keep the same email addresses — only the backend infrastructure changes from WorkMail to Exchange Online.

4. Will there be any email downtime during the migration?

   With Apps4Rent managing your migration, email disruption can be reduced to zero. We use a dual-delivery approach during the migration window: email is simultaneously delivered to both WorkMail and Exchange Online while data is syncing across. MX records are only switched exclusively to Microsoft 365 after all mailbox data has been migrated and verified. Combined with pre-lowered DNS TTL values (5 minutes), the actual cutover typically completes in under 10 minutes with no mail loss whatsoever.

5. Can I migrate contacts and calendar events — not just emails?

   Yes. In addition to email, Apps4Rent handles the migration of:

   • Contacts — exported from WorkMail as vCard (.vcf) files and imported into Exchange Online via Outlook Web App
   • Calendar events — exported as iCalendar (.ics) files and imported into Outlook Calendar or Exchange Online
   • Shared mailboxes and distribution lists — recreated in Exchange Admin Center with appropriate permissions
   • Resource mailboxes — conference rooms and equipment mailboxes recreated with correct scheduling configuration

   The IMAP migration method handles email natively. Contacts and calendars require additional export/import steps that Apps4Rent manages as part of the full-service migration package.

6. What’s the difference between IMAP migration and cutover migration for WorkMail?

   Both methods migrate email from WorkMail to Exchange Online, but with different approaches:

   • IMAP Migration: Uses the IMAP protocol to copy emails folder-by-folder from WorkMail to Exchange Online. Works with any IMAP source, relatively straightforward to configure via EAC, migrates email only (contacts and calendar handled separately). Best for organizations under 150 users.
   • Cutover Migration / PowerShell: Uses Exchange Web Services or PowerShell to migrate all mailboxes in scripted batches with greater automation and detailed logging. Better for 150+ user organizations with dedicated IT staff. Supports richer error handling and reporting.

   Apps4Rent recommends IMAP migration for most WorkMail customers given WorkMail’s native IMAP support and the straightforward tooling available in Microsoft 365 Admin Center, with PowerShell automation for larger deployments.

7. How long does the WorkMail to Microsoft 365 migration take?

   Migration timelines depend on user count and total mailbox data volume:

   • 1–25 users: 1–3 business days
   • 25–150 users: 1–3 weeks (pilot, testing, and phased rollout)
   • 150+ users: 4–8 weeks with phased migration batches

   Apps4Rent runs migrations during off-peak hours — weekends and overnights — to minimize impact on business operations. For large organizations, we run parallel batches to compress the overall timeline while maintaining data integrity throughout.

8. Do users need to reconfigure Outlook after the migration?

   If users currently access WorkMail through Outlook, their Outlook profile needs to be updated. The process is straightforward:

   • Open Outlook → File → Account Settings → Manage Profiles
   • Remove the existing WorkMail account
   • Add a new account using the Microsoft 365 email address and credentials
   • Outlook Autodiscover automatically detects Exchange Online server settings

   For Microsoft 365 Business Standard and above, users also get the latest Outlook desktop application included in the subscription — the best version of Outlook available.

9. What happens if I miss the March 31, 2027 shutdown deadline?

   Based on AWS’s official announcement, after March 31, 2027, all WorkMail accounts, console access, and stored data will be permanently terminated. AWS has not indicated any grace period, post-shutdown export window, or data recovery service.

   Do not assume your data will be retrievable after the deadline. If you cannot complete your full migration before March 2027, at minimum export your WorkMail data using AWS’s official mailbox export tool (exports to S3 in PST format) well in advance of the deadline — so your data is preserved even if you haven’t completed your Microsoft 365 migration yet.

   Apps4Rent’s migration team can begin your assessment immediately. Contact us today — it is free, it takes less than one business day, and there is no commitment required to start.