mercury security

[westsurf99]

Greetings and thank you for your assistance!

I am concerned about the security of the mercury mail server.

I have installed xampp and phplist. I have configured several users in mercury e-mail server for testing phplist e-mail listserv running on xampp. Thunderbird is installed and configured to view the e-mail sent/received by the users in mercury mail. Everything is on localhost.

Mercury is running SMTP on port 25 of my system. Thunderbird uses IMAP on port 143 to retrieve messages. I have a firewall, but I want to be sure that no one can remotely access mercury/thunderbird on my system as a way to break in. What do I need to do to secure this local e-mail testing environment? Any assistance/resources you can provide are greatly appreciated! Thank you!