IMAP Email Migration Guide

IMAP is the universal mailbox path for hosts that are not fully covered by Google or Microsoft tenant tools. It works well for cPanel, Dovecot, Courier, Titan, GoDaddy, iCloud, many ISP mailboxes, and a lot of older webmail platforms.

What To Collect

• Source IMAP server, port, TLS mode, username format, and whether an app password is required.
• Destination IMAP server, mailbox quota, account creation status, and special-folder names.
• Mailbox GB, message count, folder count, largest message size, and whether spam/trash should be copied.
• DNS/MX cutover plan if the mailbox is tied to a custom domain.

No-Custody Copy

Migration Monkey defaults to direct IMAP bridge mode. The control plane coordinates the job and records metadata, but the mail payload should flow from source mailbox to destination mailbox without resting in Migration Monkey storage.

Common Blockers

IMAP migrations usually fail because IMAP is disabled, TLS certificates are untrusted, the provider requires an app password, the destination quota is too small, throttling limits are hit, or folder names collide. The tool estimates extra credits for these constraints because they create retry and verification work.

Cutover Pattern

1. Create the destination mailbox first.
2. Run analysis and start the first copy while MX still points to the old provider.
3. Run a delta pass for messages that arrived during the first copy.
4. Change MX records after the destination mailbox verifies correctly.
5. Run a final delta pass after DNS settles.

Credit Notes

Generic IMAP is the baseline email profile: low base credits, mailbox GB overage, mailbox count overage, and smaller auth modifier than Gmail or Microsoft 365. Assisted encrypted relay is the high modifier and should only be selected when a direct bridge is not practical.