Migrating email mailboxes from another host.
How to move IMAP mailboxes — including all folders and message history — from your old host to Rivervo.
Files and databases are easy to migrate. Email is the trickier part — messages need to be transferred without losing folders, flags, or history.
Methods, in order of preference
1. imapsync (recommended, ours-side)
We run imapsync on our infrastructure to pull from old IMAP to new. Most reliable, fastest, preserves everything.
What we need:
- Old mailbox: server, port, username, password
- New mailbox: already created on Rivervo
Process:
- Open a ticket: "Please run imapsync from old@oldhost.com to new@yourdomain.com"
- We provision the new mailbox (or use existing)
- We run imapsync, monitor for errors
- Done — all messages, folders, flags transferred
Time: 5 minutes for small mailbox (under 1 GB), up to a few hours for 30+ GB.
2. Self-service via desktop client
Works without us:
- Add both old and new IMAP accounts to a desktop client (Thunderbird is the easiest)
- Wait for both to sync fully (can take an hour for big mailboxes)
- Drag-and-drop messages from old folders to new folders
- Verify counts match
- Once verified, you can remove the old account
Pros: no waiting on us, you control timing. Cons: slow for big mailboxes, easy to mess up if interrupted.
3. Manual export/import (mbox or maildir)
For mailboxes where IMAP isn't available:
- Old host: export to mbox or maildir format (usually possible via webmail "download all messages" or via Thunderbird "Save as")
- We import the mbox/maildir into your new Rivervo mailbox via SSH
Open a ticket if you go this route — we'll help.
Mailbox size considerations
| Size | Method | Time |
|---|---|---|
| Under 1 GB | imapsync (us) | 5‑15 min |
| 1‑10 GB | imapsync (us) | 30‑90 min |
| 10‑50 GB | imapsync (us, off-hours) | 2‑6 hours |
| >50 GB | imapsync split by year | half-day |
During the migration
Don't change MX records yet. Email keeps flowing to old mailbox while you're syncing. Wait until imapsync finishes, then cut over MX records.
Brief overlap is fine. During the cutover hour, mail might land in either mailbox. Worst case: 2‑3 messages need to be moved manually. Acceptable.
After migration
Update your email clients. Old credentials no longer needed. Update each device:
- Server:
mail.yourdomain.com(Rivervo) - Old credentials → delete
- Add new account with new password (Rivervo cPanel)
Update SMTP for sending. Your client needs the Rivervo SMTP settings to send mail too. See Setup email clients.
Verify SPF/DKIM/DMARC. New host means new sending IP. Update DNS records — see Setup SPF DKIM DMARC.
Common gotchas
"Folders are empty after migration." imapsync needs to re-create the folder structure. If old host used non-standard folder names (Sent Items vs Sent), the names may not match exactly. Check both root and Inbox subfolders.
"Flagged emails lost their flags." imapsync preserves IMAP flags by default. If your old IMAP server didn't expose flags properly (some older Exchange setups), they're lost.
"Sent folder doesn't sync." Some clients (Outlook especially) save Sent locally, not in IMAP. Check Sent subfolder in IMAP root vs the local Sent folder in your client.
"Big attachment won't transfer." Server limit on individual messages: 25 MB. If you have older messages with 50 MB attachments (rare), they get skipped. We can lift the limit on request for one-time migration.
Forwarders and aliases
Forwarders are recreated separately. imapsync moves messages, not forwarder rules. After mailbox migration, recreate forwarders in cPanel → Forwarders.
Catch-all addresses (anything@yourdomain.com → real mailbox): set in cPanel → Default Address → Forward to email address.