Thanks, Matt. For myself, I also found that "DNS cacheing" and "failed domain skipping" were good ideas in the lab, but bad in the real world. I had turned them off before I saw a problem with Hotmail.com, and later with Microsoft.com itself. It's a problem with Microsoft and with Ipswitch; Microsoft advertises hosts that behave in one of two bad ways: there's no host there, or there is a host but it doesn't accept mail. In both cases, Ipswitch has written IMail such that it handles the case badly, and tries to go to the same host next time.
My workaround was to host dummy domains in my own local DNS, and only populate their MX records with hosts that respond. That's weak, because at some point that list of hosts will change; meanwhile, it's worked great for months now. When that does happen, I'll make another trip to DNSReport.com and see which hosts they have responding and what their names are (Microsoft is also mixing up their revdns, helo and forward dns, or have no revdns at all ... so I fix those up too... to avoid false positives on inbound ham... yeesh). On the other topic of expanding mailhosts, I pretty well understand my own circumstances, but was fishing for experiences. A smart man learns from his own mistakes, a wise man learns from the mistakes of others, eh? As another example, I was wondering if the question would turn up anybody's negative experience in dealing with multiple declude logs, or your own experience in spammers hitting your least preferred MX record, or troubleshooting problems if everything has the same name and only the IP is different ... Andrew (there I go, fishing again!) -----Original Message----- From: Matt [mailto:[EMAIL PROTECTED] Sent: Friday, November 05, 2004 1:19 PM To: [EMAIL PROTECTED] Subject: Re: [Declude.JunkMail] OT: expanding beyond one mailhost Colbeck, Andrew wrote: >Thanks, everyone. > >I was hoping for more war stories, or specific gotchas with more ornate >configurations, so I'm suprised at the few responses. For example, >I've noted that IMail has a queuing problem with HotMail advertising MX >servers that don't actually accept mail, or that don't exist, which >could come about with normal "downtime" on a mailhost that is still >advertised in DNS. > > The Hotmail issue is really an IMail issue where they poorly implemented 'DNS caching' and 'failed domain skipping'. When you turn these off, the Hotmail issue reportedly goes away, and I'm not aware of any advantages to using them considering that Declude does about 100 times the DNS lookups on my system without issue and without caching. I'm not convinced that load balancing with multiple A records would resolve anything with this configuration either, so it is of no consequence either way as far as I can tell. Hopefully others that might implement some form of DNS caching with failed domain skipping would see fit so as to not cache records that fail. Your setup is just simply a matter of how much of your E-mail you would like to go to a particular IP, and if you wished to make use of extra weight for messages that bypass a higher priority for no good reason. I doubt that anyone here has had any issues with either running stepped priorities or a single priority with round robin load balancing. Matt -- ===================================================== MailPure custom filters for Declude JunkMail Pro. http://www.mailpure.com/software/ ===================================================== --- [This E-mail was scanned for viruses by Declude Virus (http://www.declude.com)] --- This E-mail came from the Declude.JunkMail mailing list. To unsubscribe, just send an E-mail to [EMAIL PROTECTED], and type "unsubscribe Declude.JunkMail". The archives can be found at http://www.mail-archive.com. --- [This E-mail was scanned for viruses by Declude Virus (http://www.declude.com)] --- This E-mail came from the Declude.JunkMail mailing list. To unsubscribe, just send an E-mail to [EMAIL PROTECTED], and type "unsubscribe Declude.JunkMail". The archives can be found at http://www.mail-archive.com.
