Moving domain to mailcow & IMAP sync

g4rf

Hello,

we’re on our way to move a domain with existing mailboxes to mailcow. As I want the downtime as small as possible, I like to do an IMAP sync before we DNS switch the domain.
But: If I add the domain to our mailcow, nobody of us can write e-mails to the old mail server, as mailcow will try to relay it locally.

There are two options, that might be helpful for me, but I didn’t find any documentation about them:

marking the domain as not active
using the relay option

If someboy can show me the way to the documentation would be great.

Thanks in advance,
Jan

Kevo

Don’t use the new server until the switch has been made. Just continue to use the old server.

Sync the accounts beforehand just like you said. Then when ready make the switch.

There should be no need to mark the domain inactive or relay between the servers.

Maybe I’m missing something particular about your situation?

ETNyx

Check Relay options in domain edit. If selected domain is not authoritative on MC you can check this, I usually use Relay this domain and Relay all recipients if checked it work as this:

domain.ltd have MX external.ltd. You add this domain to to your mc.ltd check those, all users of your mc.ltd that will send message to domain.ltd will by relayed to external.ltd, so normal delivery as expected to MX,..

If you check this, in a second you change your DNS to your MC uncheck this.

g4rf

@ETNyx
Thanks for the explanation, that’s the point I was looking for. Is there somewhere a documentation about that?

@Kevo
The problem is:

I have a mailbox (doesn’t matter which domain) on my mailcow from where I send my mails.
When I add a new domain to mailcow and send an e-mail from my mailcow mailbox, mailcow won’t look up the DNS MX anymore but tries to deliver it directly to this local domain.
Normally that’s okay (and fast), but for the time of a mail server change this prevents mailcow to send e-mails to the old mail server, even if it’s still in the DNS MX. And so my mails won’t receive the receipent on the old server.

It’s a special case, when communication with the owner of the IMAP sync mailbox is still important over the old mailserver.

Kevo

I missed the fact that the mailcow server is already serving existing domains. I read the initial post as a switch from an existing server to a new mailcow server. It makes way more sense now. :-)