Rainer Dorsch wrote: > Am Montag, 18. Mai 2020, 20:50:49 CEST schrieb Dan Ritter: > > Rainer Dorsch wrote: > > > I was more concerned about the outgoing server configured in the email > > > clients and used to send main from my domain (at least so far I did not > > > understand that they can make use of the MX record). > > > > It depends on the MTA you choose for your email clients, but > > unless you choose the very simplest systems, they can be > > configured to look up the MX record and use that. (Postfix has a > > fallback_relay option, Exim can accept multiple hosts in a > > route_list statement, and so forth.) > > Thanks again for your reply. > > But what about a client like Thunderbird, kmail or Android mail clients. They > need an *outgoing* server. > > Do they handle MX records?
No, if you need high availability for those, you need load balancing. DNS is not a good way of doing that; consider ldirectord or haproxy or pound, and remember that you will need at least two of those machines in a STONITH configuration. In any of these cases, you'll configure all your mail servers to answer as smtp.domain with the same TLS certificate. -dsr-
