Mailbox data, new mail routing and account settings require separate acceptance checks; keep the source until failures and catch-up are resolved.
Move email in two coordinated parts: copy existing data and change where new mail arrives. Create the destination accounts, test a pilot import and verify delivery before retiring the old service. No generic procedure can guarantee that every message or account setting will transfer.
1. Inventory mailboxes and everything around them
List mailboxes, storage use, aliases, groups, forwarding, shared addresses, rules and sending applications. Record contacts, calendars and tasks separately. Ask whether the migration tool copies them; an IMAP mail import is not proof that the rest of the account moves.
Identify accounts you are authorized to migrate and secure any exported data. Check the destination’s licence, storage and import limits before purchase. A domain mailbox and a newsletter platform solve different problems; read email hosting versus email marketing if the product categories are unclear.
2. Match the migration method to the data
| Destination tool | Important documented constraint |
|---|---|
| Google Workspace Data import, IMAP | Up to 100 users per import; messages plus attachments exceeding 25 MB are excluded. |
| Microsoft Exchange Online IMAP | Up to 500,000 items per mailbox and messages up to 35 MB; contacts, calendars and tasks are not copied. |
| Zoho Mail IMAP | Storage capacity and selected folders affect the import; Sync availability is in phased rollout. |
These are observations from current official documentation, not tests of provider accounts. They belong to particular tools and can change. A service-specific migration may support more data than IMAP, so choose the supported method for the actual source and destination. Record excluded items and how you will preserve them.
3. Create destinations and run a pilot
Create the needed destination mailboxes and assign licences before starting. Use a representative mailbox with old messages, nested folders, attachments and non-English text. Connect through the provider’s supported secure authentication flow; do not disable certificate checks to force an import through.
Keep DNS delivery on the old provider during the initial copy unless the documented migration method requires otherwise. Compare selected folders and representative messages, including their dates, attachments and read state. Folder counts alone can differ because providers represent labels and folders differently.
- Can the user find recent and old important messages?
- Are large or blocked attachments reported, rather than silently assumed present?
- Do contacts, calendars, shared mailboxes and rules have a separate migration or rebuild plan?
- Is there enough destination storage for imported data and incoming mail?
4. Switch incoming delivery at an agreed time
Use the destination provider’s exact MX instructions and configure its authorized sending requirements. Recreate and verify aliases, groups and sending applications as needed; IMAP does not promise to transfer these settings. Tell users when to start using the new mailbox and how to report missing data.
Send test messages to and from external mailboxes. Verify important shared addresses and mobile clients. A successful import proves neither incoming delivery nor outgoing authentication. Keep the old service accessible while cached DNS and new messages settle.
5. Catch up changes and inspect failures
If the selected tool supports a follow-up or delta pass, use its current documented method to capture messages added during migration. Check availability and duplicate handling rather than assuming every provider has a Sync button. Review reports per mailbox and folder; retry genuine failures only after understanding the cause.
Keep an explicit list of excluded messages and data. Resolve each item through a supported export, alternative import or retained archive. Do not describe a migration as complete while unresolved failures remain.
6. Retire the old service deliberately
Agree a retention period and confirm user acceptance before cancellation. Keep access to necessary historical records and document the new administrator and recovery contacts. If you reverse MX delivery, new mail can split across providers; a rollback requires a reconciliation plan, not just a DNS change.
Our small-team email buying guide helps compare the ongoing service. Migration capability and assistance can matter more than saving a small amount on the first invoice.
Costs alongside this guide
Business mailboxes
Fastmail · Standard — annual
- Initial term & commitment
- Initial term amountUS$60.0012 months termUS$5.00per user per month equivalent; 12 months prepaid
- Renewal
Taxes excluded
Price observed 2026-10-16
Plan details & sources
Custom-domain business mail with third-party email apps.
50 GB mail/calendar/contacts and 10 GB files per user; domain registration costs separate.
Choose another option if: You need the larger Professional storage allocation or configured retention archive.
United States USD public pricing reference · Taxes excluded
Published 12-month prepaid total per user; tax excluded.
Renewal: Future renewal amount and invoice term not confirmed.
Taxes excluded
Prices checked 2026-10-16Official price source ↗Observed 2026-10-16
Official price evidence ↗Other researched options
USD · US / global observations
Namecheap Private Email
Namecheap Private Email · Launch
- Initial term & commitment
- Initial term amountUS$11.8812 months termUS$0.99rounded monthly equivalent; prepaid
- Renewal
- US$14.88total for 12 months
Check local tax at checkout
Price observed 2026-10-16
Plan details & sources
A team needing the included number of separate inboxes.
1 mailbox; 5 GB per mailbox; 10 aliases.
Choose another option if: You need a newsletter service or the mailbox count does not fit.
Global USD reference · Check local tax at checkout
Check local tax at checkout
Prices checked 2026-10-16Official price source ↗Renewal billing source ↗- Custom domain: Included. Use your own registered domain
- Mailbox capacity: Included. 1 mailbox; 5 GB
- Calendar: Included. Built-in webmail calendar with CalDAV sync
- Custom domain, Mailbox capacity ↗Features checked 2026-10-07
- Calendar ↗Features checked 2026-10-08
Observed 2026-10-16
Official price evidence ↗Namecheap Private Email
Namecheap Private Email · Expand
- Initial term & commitment
- Initial term amountUS$31.4412 months termUS$2.62rounded monthly equivalent; prepaid
- Renewal
- US$41.88total for 12 months
Check local tax at checkout
Price observed 2026-10-07 · Recheck due
Plan details & sources
A team needing the included number of separate inboxes.
3 mailboxes; 10 GB each; 50 aliases each.
Choose another option if: You need a newsletter service or the mailbox count does not fit.
Global USD reference · Check local tax at checkout
Check local tax at checkout
Prices checked 2026-10-07 · recheck dueOfficial price source ↗Renewal billing source ↗- Custom domain: Included. Use your own registered domain
- Mailbox capacity: Included. 3 mailboxes; 10 GB each
- Calendar: Included. Built-in webmail calendar with CalDAV sync
- Custom domain, Mailbox capacity ↗Features checked 2026-10-07
- Calendar ↗Features checked 2026-10-08
Observed 2026-10-07 · Recheck due
Official price evidence ↗Recorded prices can change. Check eligibility, taxes and the current full bill with the provider. Different currencies and services are shown separately.
Sources and verification
Editorial review 2026-10-07. Source check dates are recorded separately. Notes describe what each source supports and its limits.
View sources
- Google Workspace data import overviewChecked Destination accounts and licences are required; IMAP and message-size limits.
Limits: Email import does not establish calendar, contact or alias migration. - Microsoft Exchange Online IMAP migrationChecked IMAP copies mail folders, not contacts/calendars/tasks; per-mailbox limits.
Limits: These limits belong to Microsoft migration tooling, not IMAP universally. - Zoho Mail IMAP migrationChecked Destination accounts, capacity, reports and retry/sync options.
Limits: Sync/Sync All is in phased rollout; do not bypass certificate validation.