DKIM multiple mail servers

We currently have a single mail server (RHEL/sendmail) for all mail "mail.example.com". We have added a second mail server "email.example.com". We intend to use this for bulk email, while "mail.example.com" remains for transaction and internal mail.

We have DKIM set up for "mail.example.com", but I need to set up DKIM for "email.example.com".

My question is this: Can I use the same TXT record I have for "mail.example.com" for "email.example.com" and modify some DKIM/milter/sendmail settings? Or do I have to create an entirely seperate TXT record and key.

Solution 1:

You can reuse the same records and keys for the new server. It's best practice to setup new keys and records for each server however; any compromise on a single server leaves the others unaffected.