Migrate from Cyrus to Stalwart?

[sgofferj]

I'm running Postfix/Cyrus as my main private mailserver for maybe 25 years or so. I have been thinking already for a while to find something new, especially something that could run in docker. The main thing that keeps me off, though, is that I would like to migrate all my mailboxes - if possible automatically. I once had to move Cyrus from one machine to another and that was a huge hassle because apparently I made some mistake and then had to move tens of thousands of mails manually... I only have a handful of mailboxes (family and some shared folders / role accounts) but lots of subfolders.
Is there any way to import the mailboxes and folders from an existing Cyrus instance? My Cyrus uses simple native harddisk storage, no databases. Google didn't really spit out much about his topic...

[williamdes]

Similar to #551

Also see #836
fetchmail seems to help some users

I have the same issue than you postfix/dovecot. That's why I was working on #600 but to export
I guess some Rust code could be made to import a SMTP mailbox.

[mdecimus]

Hi, you have two options to migrate, using imapsync or importing the mailboxes using the CLI.

[sgofferj]

Unfortunately, Cyrus does not use maildir or mbox. That would be too easy... 🙄

[mdecimus]

Then I guess the only options are imapsync or using a tool that export Cyrus mailboxes to Maildir.

[jayknyn]

imapsync is a great tool for migrating email accounts from one mailserver to another (or even from one account to another on the same mailserver). But it does require that both mailservers are up and running at the same time and their IMAP port is reachable. If you're migrating your mailserver domain, maybe create a temporary name for the new Stalwart mailserver, like mail2.domain.com and then after the migration, change the domain back to mail.domain.com.

Here's a docker based command that I use:

docker run --rm -v /opt/mailserver/imapsynclog:/var/tmp/LOG_imapsync gilleslamiral/imapsync imapsync \
--addheader --log --automap \
--host1 mail.domain1.com --user1 [email protected] --password1 'secret1' \
--host2 mail.domain2.com --user2 [email protected] --password2 'secret2' \
--nofoldersizes --nofoldersizesatend \
--search1 "SENTSINCE 24-Feb-2023 SENTBEFORE 28-Feb-2023" \
--dry

The --search1 is an optional param if you want to migrate in batches, which I recommend to make sure that everything looks good on the new mailserver before migrating everything over, so you could set a narrow date range to migrate over for a test. And the --dry will do a full dry run without migrating any mails over.

[sgofferj]

I'll have a look but the lack of direct migration features is somewhat discouraging. It increases complexity quite a bit.

[mdecimus]

There are plans to create full migration tools for Cyrus and Dovecot but this won't be done until version 1.0.0 is released next year. In the meantime the only alternatives are imapsync or using Maildir as the intermediate format. Perhaps you can export all Cyrus mailboxes to Maildir and then import those Maildirs into Stalwart?