Answers

What port is SMTP running on? 25

What command do we use to do this? msfconsole

Let's search for the module "smtp_version", what's it's full module name? auxiliary/scanner/smtp/smtp_version

Great, now- select the module and list the options. How do we do this? options

Have a look through the options, does everything seem correct? What is the option we need to set? rhosts

What's the system mail name? polosmtp.home

What Mail Transfer Agent (MTA) is running the SMTP server? Postfix

Let's search for the module "smtp_enum", what's it's full module name? auxiliary/scanner/smtp/smtp_enum

What option do we need to set to the wordlist's path? USER_FILE

Once we've set this option, what is the other essential paramater we need to set? RHOSTS

Okay! Now that's finished, what username is returned? administrator