> Also if a MX refuse you because of some blacklist then remove > thoses mails from the queue and send you a mail alert so you can > investigate why destination refused your mail.
It's important not to fail an email on a first refusal, due to the wide usage of 'greylisting' where the SMTP server rejects the first email attempt and then allows a second attempt, typically 10 to 15 minutes later. Sometimes the response mentions greylisting, but some SMTP servers don't even do that. MAIL FROM: <nursery...@englishmotorsports.com> 250 OK <nursery...@englishmotorsports.com> Sender ok RCPT TO: <i...@magsys.co.uk> 451 Greylisted, please try again in 600 seconds Once an email has been sent successfully, the server adds the sender to an internal list so future email is not delayed. Greylisting is very successful in stopping spam, at least for the moment, it stops 500 to 1,000 spams a day here. However have a couple of Delphi applications that currently sent email without using a queue or a 15 minute delay, which really need updating to cope with greylisting. Angus -- To unsubscribe or change your settings for TWSocket mailing list please goto http://lists.elists.org/cgi-bin/mailman/listinfo/twsocket Visit our website at http://www.overbyte.be
