A non-default configuration in TenFour TFS Gateway 4.0 allows an attacker to cause a denial of service via messages with incorrect sender and recipient addresses, which causes the gateway to continuously try to return the message every 10 seconds.

A buffer overflow in TenFour TFS Gateway SMTP mail server 3.2 allows an attacker to crash the mail server and possibly execute arbitrary code by offering more than 128 bytes in a MAIL FROM string.