Greet pause

From ASRG
Anti-spam technique: Greet pause
Date of first use: early 2000s
Effectiveness: Medium
Popularity: Medium
Difficulty of implementation: Easy
Where implemented: MTA
Harm: Low to Medium


Greet pause simply adds a delay before a server sends the initial banner. Some spamware is very impatient and will drop the connection if it doesn't see a banner within a few seconds.

Some servers have used a pause as long as a full minute which is reported to deter large amounts of spam, at the cost of considerable delays in legitimate mail. A greet pause of 5 to 10 seconds appears to deter some spam without unduly delaying or losing legitimate mail. It's also possible to use greet pause in combination with Greylisting, only pausing on connections from clients that haven't yet successfully delivered a message.

Greet pause is also sometimes use in combination with Early talker detection.