Alex,

Typically this occurs when you have identical hostnames set for some of your domains. Consider this: 

 1. I set my domain default hostname to mail.test.local, which is also the hostname of the test.local domain

2. I create 2 new domains, new.local and newer.local, which will have mail.test.local as their default hostnames

3. If I check automatic certificates, I'll have 3 mail.test.local certificates, although if I double click them, i can see they are bound to different domains(test.local, new.local, and newer.local, respectively). 

This is expected behavior when using duplicate hostnames, but it shouldn't cause any issues! If you want to prevent this behavior, I'd set the default hostname for domains to mail.%domain%, which will prevent duplicate certificates, instead generating a unique set per domain. 

I hope this helps! 

Hi Jorel,

thanks for the update - well the issue i forgot to mention, as soon you delete an domain it deletes in IIS the domain of the main host and the mail server isn't avalibe anymore, but if we can use this option it will work fine. For what is the "H o s t n a m e " from a technical view used or important? I don't see any application for this "field" or "information" in each Domain setting?!

Greetings

When you enable automatic certificates during a new installation, it creates a certificate for the server hostname itself (e.g., mail.mymail.com). This is a reasonable default to ensure basic functionality.

When you add a new domain (e.g., newdomain.com), SmarterMail automatically generates certificates for the relevant subdomains like autodiscover.newdomain.com, mail.newdomain.com, and webmail.newdomain.com.

However, it also creates an additional certificate for mail.mymail.com (your server hostname) for the new domain. This might seem unnecessary.