When working with mail servers, it is handy to be able to check to ensure your configuration is working as expected. To that end, here are some test strings that you can use to check it out:
SPAM: XJS*C4JDBQADN1.NSBN3*2IDNEN*GTUBE-STANDARD-ANTI-UBE-TEST-EMAIL*C.34X
VIRUS: X5O!P%@AP[4\PZX54(P^)7CC)7}$EICAR-STANDARD-ANTIVIRUS-TEST-FILE!$H+H*