> > Hello, > > > > I have a silly question, but in an effort to resolve an issue > > I just have to ask. > > > > Every so often one of our clients sends out a mail message > > via their website, which gets routed to one of our qmail > > servers for delivery (approx 800 messages). > > > > Occasionally when mail is sent during the day, there are > > several remote recipients who indicate they are receiving > > multiple copies of the message, sometimes up to 10. > > > > There are several consistent remote users who complain > > and the remainder are random (as far as I can tell) they > > are different users each time. > > > > I will add, that sending an automated email to the same > > 800 users during non peak hours (3-4am) does not result > > in duplicates > > > > My question is does spamdyke impose a timeout on the > > response of the remote smtp server that would trigger > > qmail to resend the email again, thus producing the > > duplication of messages? > > > > Thanks > > > > You're close, but not quite there. > > Spamdyke (v4) can impose two different timeouts depending on the > configuration, one for the total session and one for inactivity. However, > spamdyke is only active on *incoming* smtp sessions, so spamdyke doesn't > come into play in this scenario. > > What's probably happening is that during the day your server or bandwidth > are overloaded to the point where a receiving server times out, qmail sees > that there was no acknowledgment of successful transmission, and > reschedules > delivery, resulting in the duplicate. I'd try throttling back the number > of > concurrent remote tasks. You should have a > /var/qmail/control/concurrencyremote file that specifies this value. > See "man qmail-send" for details. > > -- > -Eric 'shubes'
I might add to Eric's suggestion that possibly you have "SpamAssassin" included in the mix, and you are potentially causing the messages being submitted to "Timeout" SpamAssassin, which I've seen cause duplicates on my server. (Usually inbound mail, during large spam bot attacks). Any easy way to determine this is to look at the message headers on the first of the duplicate e-mails (Not the last one they get) and see if the SpamAssassin scores are (?/?), indicating SpamAssassin "Timed out". If so, that's likely your issue. This issue causes what Eric refers to, but in reverse. You're web server sends the message to your mail server, it times out on accepting it, and the web server re-queues it for delivery, and sends it again...So, in fact, your web server may be sending it twice, and qmail is simply taking it twice and delivering it. If it turns out to be this, simply exempt your web server from SpamAssassin in your SpamAssassin config, or find a way to lower the load on your mail server during the 800 simultaneous message deliveries. Michael J. Colvin NorCal Internet Services www.norcalisp.com _______________________________________________ spamdyke-users mailing list spamdyke-users@spamdyke.org http://www.spamdyke.org/mailman/listinfo/spamdyke-users
