James B. Byrne wrote:
I am getting large numbers of these types of messages in my maillog files:
somehost.hotmail.com [65.54.246.97] did not issue MAIL/EXPN/VRFY/ETRN during connection to MTA
on both of our external machines beginning on the same date. These hosts sit on different netblocks and on both machines the sendmail.cf files date from Jan 09, 2007.
The last successfull connection from any hotmail acocunt was on Jan 15 at 13:17:29. The first failure was recorded on Jan 15 at 18:36:46. Does anybody have any idea what is going on? We are now getting reports that hotmail users are getting a delayed transmission warning and then a failure message. Is this a sender's issue or our local configuration issue?
ANY help regarding this matter would be most appreciated. If you feel that sendmail related items should not be discussed on the list then please contact me privately.
It sounds like they are dropping the connection before getting very far in the conversation. This can be caused by either end, but the likely place to check is any spam-screening operations you might be doing that could impose a delay on your initial greeting, like having greet-pause set or using one of the network blackhole services that could be taking a long time to validate this address. Other places that can add delay are your reverse DNS lookup and an ident query on the socket. The latter can cause a long timeout if it hits a firewall that silently discards it without an ICMP 'denied' response.