DNS for e-mail config with multiple Cloudrons on one domain

[potemkin_ai]

Hello! I would use some help, if possible.
I have a few Cloudrons on a single domain, for a different purpose under various sub-domains.

If I follow the instruction from each cloudron and configure e-mail as per the requirements (by the way, thanks for making it so easy!!) then 3 of the Cloudrons remains unhappy about the configuration.

The problem is with DKIM & SKF mail records - every server wants the very same records (cloudron._domainkey & @) to be different, so they end up conflicting with each other.

How do I merry them happily together?
And, btw, is there any way to remove 'cloudron' from the dns name? Just for the security purposes.

Thanks a lot!

[BrutalBirdie]

@potemkin_ai well I would not have multiple mail servers in the first place.
I would have the top level Cloudron as the mail server and configure all other to relay to that one.
But that would still not include all users.

This is why I got a ldap server from where I sync my cloudrons.
1 master for ldap, 1 master for mail.

That is how I do it.

[potemkin_ai]

@brutalbirdie I don't need multiple servers as well, just want to make sure I have a way to get all e-mail notifications from all of my instances.

Using my 'primary' instance for that purpose seems to be an option, indeed - thank you.

Am I right in understanding that this would require me to create special 'service' accounts on my 'primary' cloudron for every other cloudron instance inside my domain and then configure all of the other cloudrons to send mail using direct smtp?

And by doing so, my other cloudron's won't need SPF and other mail stuff, is that correct?

[potemkin_ai]

@brutalbirdie I would really use your help on this final step - how to properly configure CloudRons to send e-mail via my primary Cloudron!

[BrutalBirdie]

@potemkin_ai
I am not sure if you can do that properly if you don't have one central LDAP Server.
Since all my users and groups are present on all cloudron instances.

But ok I will try. All mentioned domains are manual configured!
Otherwise they instances will overwrite each other if you configure the same domain.

My server my.primary_mail_cloudron.com is running all users and groups and has all post boxes configured.
Another instance my.secondary_node_cloudron.com has the same domain configured primary_mail_cloudron.com

The secondary has for the domain primary_mail_cloudron.com outbound only and has this configured.

It's... complicated.

[potemkin_ai]

@brutalbirdie ok, thank you - I've got the idea!