John Rudd wrote:
1) Greet_Delay (default 30 seconds) -- had some brief false positives with mac.com, but they fixed their MTA to stop being so impatient.
You might want to keep in mind that some MTAs that do callout verification use 30 seconds as the default timeout, and if you make them wait too long you may have trouble sending mail to them. I think this is too short, personally, but it's the default in Exim. Incidentally, if you delay all hosts, I think you'll find that some of AOL's servers get disconnected.
Personally, I don't delay all hosts, just ones that meet one of these conditions:
- Listed in a DNSBL as being a spam source or dynamic IP
- No reverse DNS
Also, if they give me an invalid recipient, they get a 60-second penalty before they can try another one.
