What software does that mail server run

I'm happy to help! However, I need more information about the mail server you're referring to. Could you please provide more context or details about the mail server, such as:

  1. What type of mail server is it (e.g., Exchange, Postfix, Sendmail, etc.)?
  2. Is it a physical server or a virtual machine?
  3. Is it running on a specific operating system (e.g., Windows, Linux, etc.)?
  4. Are there any specific software or services running on the mail server that you're interested in?

Once I have more information, I can try to help you identify the software that the mail server runs.