Thank you all for this valuable information and advice. I appreciate it. I have been thinking a lot about this over the past few days. Currently we have Backup MX servers (Windows-based) in place for a few of our Windows-based mail servers and they have been working quite well. We really don't have much of a problem with spam because Message Sniffer, SpamAssassin for Windows, and a few other AS/AV programs we are using are doing a really great job in keeping spam to a minimum.
I was chatting with one of my colleagues about the advice that you guys and the Postfix list members provided. A saw a few times during those posts that MX backup servers are probably not a good idea in general and the reasons all seem to be pointing to the spammer problem. Since this is the case, I brought up the subject of anti-spam gateways since we use those as well in our environment. In the event of a primary server outage, our gateways spool the mail until the primary server becomes available again, however, if the gateway had an outage or failure, we would be in the same boat. The mail would be rejected/bounced. I'm aware that most commercial gateways use a round-robin so that they can essentially be "always up", but what about the smaller clients who run their own mail server from their offices and cannot afford a good gateway solution? I think folks in that situation would benefit from a backup MX. That is why we implement them for a lot of our smaller clients. So far, so good. :) With that being said, besides the issues with spammers which we feel we have a good handle on, are there any other reasons why a backup MX is still not a good idea? Thanks again! On Wed, Apr 8, 2020 at 6:48 AM Gedalya via Exim-users <[email protected]> wrote: > On 4/8/20 4:33 AM, Andrew C Aitchison via Exim-users wrote: > > > > Exim does recipient callouts and cutthrough delivery. > > Are either of these useful for an MX backup ? > > Callout caching can be potentially useful when the primary is down. Not a > complete solution of course. > > > -- > ## List details at https://lists.exim.org/mailman/listinfo/exim-users > ## Exim details at http://www.exim.org/ > ## Please use the Wiki with this list - http://wiki.exim.org/ > -- ## List details at https://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
