Migrating mail accounts to xaweho

Mail migration is trickier than website migration: you don’t want to lose mail, get duplicate delivery, or go offline for long. Here’s how we do it — with IMAP sync, a well-timed MX switch and parallel operation during the move.

The concept: IMAP sync and MX switch

The task has two parts:

1. Copy existing mail: all old mail from the old IMAP server to the new one
2. Redirect new mail: change the MX record so incoming mail goes to the new server

These two steps can run separately — sync first, then switch, or the other way around. Our recommendation: both in parallel with a short transition period.

Preparation

Collecting the data

For every mail address at the old host, we need:

• Mail address (e.g. info@deinedomain.de)
• Password
• IMAP server address (e.g. mail.deinedomain.de or imap.alterhoster.de)
• IMAP port (typically 993 with SSL)

Plus, for you:

• a list of all active mail addresses (aliases too)
• an estimated volume (small mailboxes < 1 GB, larger ones several GB)

Creating the mailboxes with us

We create the matching Plesk mailbox for every mail address. More in Creating a mailbox.

Important: same password as at the old host — makes the later mail client switch easier.

Migration with imapsync

We use the tool imapsync (open source, very robust). It copies mail 1:1 from the old IMAP server to the new one, including:

• folder structure
• read/unread status
• flags / labels
• date stamps

The classic command:

imapsync \
  --host1 mail.alterhoster.de --user1 info@deinedomain.de --password1 ALTPASS \
  --host2 mail.deinedomain.de --user2 info@deinedomain.de --password2 NEUPASS \
  --ssl1 --ssl2

We run this automated for all mailboxes.

Duration: ~1-2 minutes per 1,000 mails. A big mailbox with 100,000 mails: 2-3 hours.

Migration schedule (with our help)

Day X-7

• You send a migration ticket with the address list and credentials
• We create the Plesk mailboxes
• We run the first sync — copying all existing mail

Day X-1

• We run a second sync for the mail that arrived since the first one
• You spot-check: open a few mailboxes in our webmail — everything there?

Day X (the switch)

• DNS: switch the MX record to our mail servers
• DNS propagation: 1-24 hours until active worldwide
• During propagation: a third sync round, in case anything still arrives at the old host

Day X+1

• All incoming mail arrives with us
• You switch your mail clients (Outlook/iPhone/etc.) to the new server
• If a mail is still sitting at the old host: a fourth sync run to be safe

Day X+7

• The old hosting account can be canceled
• Mail migration complete

Switching mail clients

During DNS propagation:

• some mail clients still fetch from the old server
• some already from the new one
• the mail is in sync, so it doesn’t matter

Once propagation is complete: enter the new IMAP/SMTP server details in your mail client. More in Setting up mail in your mail client.

DNS — what changes

For the MX switch, you change:

@ MX 10 mail.deinedomain.de.    (old value)

to:

@ MX 10 mail.web1.xaweho.de.   (new value, depending on your server)

Plus an SPF adjustment:

@ TXT "v=spf1 mx ip4:<unsere-mail-server-IP> -all"

DKIM and DMARC come with the Plesk standard.

With xaweho DNS hosting: we do all of it automatically. With third-party DNS: you have to adjust it manually.

Pitfalls

Mail arrives twice

Rare, but possible with long DNS propagation. A mail gets delivered both at the old host (TTL-cached) and with us.

Fix: keep imapsync running after the MX switch — it deduplicates on the receiving side. Also, receiving twice is a mail client matter (it shows them as two separate mails).

Huge mailboxes take hours

Mailboxes with 50 GB+: the sync takes long. We batch per mailbox in the background — you can keep working normally in the meantime.

Odd sync problems with some mail servers

Some old hosts have IMAP bugs (Office 365 occasionally has quirks with huge folder lists, commercial servers with custom limits).

Fix: imapsync has workarounds for the common special cases. For real bugs: open a ticket, we’ll tinker.

Aliases vs. real mailboxes

At the old host: info@ is an alias forwarding to mueller@? With us: existing aliases stay aliases. The mail content sits in the target mailbox.

We replicate the setup structure 1:1.

Catch-all from old to new

If catch-all was active at the old host: every possible random address is “real”.

During migration: only addresses with actual mail get synced. Catch-all behavior on our side has to be enabled separately.

In an emergency: the old server as fallback

If mail is missing or problems show up after the migration: the old hosting account usually still exists for 7-30 days (depending on the provider’s cancellation terms).

We can then run another sync or reset a specific mailbox.

Recommendation: don’t cancel the old account before day X+14.

Frequently asked questions

Do spam folders get migrated too? Yes, 1:1 including the spam folder. On request only inbox + sent + your own folders — a filter rule in imapsync.

What if I don’t know the mail passwords at the old host? Reset them at the old host, or set new ones, then give them to us. To be safe: the reset at the old host is the first step.

Does this also work for Office 365 / Google Workspace? Yes. Both have IMAP access (enabled on request). Office 365 needs an “app password” because of 2FA.

What does it cost? Mail migration is part of our relocation service for a €49 flat fee — all mailboxes included. For very large setups (50+ mailboxes each >10 GB) we’ll tell you in advance if it’s going to be more.

Mail rules / filters — do they come along? Sieve filters at the old host are their own configuration. We can rebuild them on request if you give them to us. Standard: the migration replicates mail only, not filters.

Calendars and contacts too? Plesk has no CalDAV/CardDAV server — calendars/contacts are not migrated. If you need that: a separate Mailcow server or Nextcloud.

Mail aliases at the old provider? We replicate them 1:1 as Plesk aliases.

What about SMTP sending history? Outgoing mail sits in the “Sent” folder (server-side). imapsync brings it along. Server-level mail sending logs stay with the old provider — not migrated.

What’s next

• Migrating your website to xaweho
• Setting up mail in your mail client
• Creating a mailbox