Joshua, C.S. Chen wrote: > Hi folks, > I am using spamassassin 3.1.0 and it works well. Now in my institute, > we have 2 mx (mail servers) see it's dns record > > myinstitute.edu.tw. 300 IN MX 100 mail2.myinstitute.edu.tw. > myinstitute.edu.tw. 300 IN MX 2 mail1.myinstitute.edu.tw. > > > > Now in most cases, spam goes to mail1 and got dropped. This is great. > But then the spam tries to go ahead for mail2, and I did not enable > mail2 for spamassassin (because it is mainly for redundancy, and not > powerful enough). This makes mail2 extremely busy to send reply to the > spammer of user unknown or other reporting messages. > > My question is, if I don't want mail2 to run spamassassin, just for > relaying messages to mail1 (as it's main purpose--redundancy), how > can I configure mail2 "NOT TO" reply the spammer for the undelivery?
If you are going to have a secondary, it should have the same spam/virus checking abilities as the primary. Quite a bit of spam these days will be sent to the secondary servers first to exploit this exact problem. If mail2 just accepts mail and then forwards it to mail1, you may want to consider dropping mail2 entirely. If mail1 goes down, incoming mail should still be held for at least a couple of days on the sending server. So unless mail2 is also capable of servicing your local users while mail1 is down, you are not getting all that much benefit from it. Especially considering the spam and DSN headaches. Consider this... With a secondary: - Secondary accepts incoming mail - Primary rejects the mail as spam/virus/no such user/etc - It is now the Secondary's responsibility to send a bounce back to the sender - Secondary's mail queue fills up with DSN messages - And since you cannot be sure of the reply address in the email, all of those messages may not even be going to the proper place. or - Secondary accepts incoming mail - Primary is down - Secondary holds the mail until the Primary comes up - See above for the results Without a secondary: - Primary rejects the mail as spam/virus/no such user/etc - It is now the sending server's responsibility to deal with the bounce or - Primary is down - Sending server will hold the mail (generally 3-7 days) - When the Primary comes back up, see above Granted, you have more control over holding the mail with a secondary, but realistically, how often and for how long do you expect your main mailserver to be down? If it is down frequently, or for more than a day or so, then you have more to worry about than a mail queue clogged with spam DSN's. I would suggest that you either: 1) Get rid of the secondary 2) Make the secondary capable of rejecting messages based on spam, virus, unknown user, etc the same way the primary does. 3) Find a way to have the secondary only accept mail when the primary is down. -- Bowie
