PCCVDI SolutionsMigrating from on-premises Exchange to Microsoft 365 is one of the most common enterprise IT projects in India right now. When done correctly, it is low-risk and delivers immediate benefits: no server maintenance, 99.9% uptime SLA, and access to the full Microsoft 365 productivity suite. When done incorrectly, you get email downtime, lost calendar data, and angry executives.
Microsoft 365 Business Basic (₹125/user/month) includes Exchange Online, Teams, SharePoint, and OneDrive 1TB. For most Indian SMEs, this is the right starting point. Upgrade to Business Standard (₹660/user/month) if you need desktop Office applications.
Pre-Migration Checklist
- Audit your current Exchange environment: version, mailbox count, size, public folders
- Inventory distribution groups, shared mailboxes, and resource mailboxes (rooms/equipment)
- Check DNS TTLs — lower to 300 seconds (5 min) 48 hours before cutover
- Verify your domain is not blacklisted (check MXToolbox before starting)
- Ensure Azure AD Connect is installed if you have on-premises Active Directory
- Purchase and assign M365 licences before starting migration
- Create a test mailbox in M365 and verify mail flow before migrating production
DNS Records You Must Configure
Incorrect DNS is the #1 cause of M365 migration failures. Configure these records in your domain registrar before cutover:
Migration Methods
| Method | Best for | Downtime risk | Duration |
|---|---|---|---|
| Cutover migration | <150 mailboxes, Exchange 2010+ | Medium (1–2 hr cutover window) | 1–3 days |
| Staged migration | 150–2000 mailboxes | Low (batches over weeks) | 2–8 weeks |
| Hybrid migration (HCM) | Large orgs, coexistence needed | Very low (move individual mailboxes) | Months |
| IMAP migration | Non-Exchange (cPanel, G Suite) | Low | 1–4 weeks |
| Third-party tool (BitTitan) | Any size, complex environments | Low | Flexible |
Shared Mailboxes and Distribution Lists
Shared mailboxes (support@, info@, accounts@) and distribution lists often get neglected until after migration. Migrate these before user mailboxes — they are lower risk and expose DNS or permission issues early.
- Shared mailboxes under 50GB are free in M365 — no additional licence needed
- Shared mailboxes over 50GB require an Exchange Online Plan 2 licence (or M365 Business Basic)
- Distribution lists migrate as Mail-Enabled Security Groups — verify membership after migration
- Dynamic distribution groups must be recreated manually — they do not migrate automatically
- Room and equipment mailboxes: create as Resource Mailboxes in M365 Admin Centre
Licensing Guide for Indian Companies
| Plan | Price/user/month | Includes | Best for |
|---|---|---|---|
| M365 Business Basic | ₹125 | Exchange, Teams, SharePoint, OneDrive 1TB, web Office | Teams using web or mobile only |
| M365 Business Standard | ₹660 | All Basic + desktop Office apps (Word, Excel, PowerPoint) | Most businesses |
| M365 Business Premium | ₹1,300 | All Standard + Intune MDM, Defender, Azure AD P1 | Security-conscious SMEs |
| M365 E3 | ₹2,400 | Enterprise features, E-Discovery, 100GB mailbox | Enterprises with compliance needs |
Post-Migration Verification Checklist
- Send test emails from external Gmail/Yahoo accounts and verify receipt
- Check email signatures are intact (HTML signatures sometimes break on migration)
- Verify calendar sharing and free/busy lookup works across mailboxes
- Test Outlook auto-configure on a fresh Windows machine (should discover settings automatically)
- Verify mobile device email (iOS Mail, Android Gmail) reconnects correctly
- Check that distribution list emails deliver to all members
- Run MXToolbox MX Lookup and confirm MX records point to Microsoft
- Check DKIM signing in M365 Security Centre — enable and allow 48 hours to propagate
- Monitor spam/junk folders for first 2 weeks — false positives are common post-migration
Run the Microsoft Remote Connectivity Analyzer (testconnectivity.microsoft.com) before and after migration. It validates MX, Autodiscover, SPF, DKIM, and SMTP connectivity in one tool — and is free.