On Thu, 18 May 2006, Marc Perkel wrote:
| On rare occasions a user will get several duplicate messages. What
| appears to be happening is that the sending server completes the
| transfer and Exim accepts it, but the sending server thinks the delivery
| failed and therefore resends the same message.
Check out RFC 1047, which explains why duplicates occur where DATA-time
scanning takes too long...
This is SMTP's built-in fail-safe mechanism - it's better than the
alternative of lost mails.
| It only happens with specific servers. The duplicates always come from
| the same place.
Likely these sending servers have particularly low timeouts.
You may want to:
- tune settings so senders are defered earlier, if box is busy
- find (yet more...) ways to pass less to SpamAssassin
