Bill Cole wrote: > On 16 Sep 2019, at 7:44, Helmut Schneider wrote: > > > I already created an entry in the hosts file without success. > > This (name resolution) is the ideal place to address your problem. If > your OS name resolver is not using an entry in your hosts file, it > may be because the entry isn't correct OR because your nsswitch.conf > file directs the resolver to ask DNS first. If you're running a > system that does not use nsswitch.conf and can't be made to check > local files first, you may benefit from running a recursing/caching > resolver daemon like Unbound which supports its own local data.
Ubuntu 16. > Note that hosts file entries are ONLY for A and AAAA resolution, NOT > MX resolution, so if you are routing m ail in Postfix via a mechanism > that does MX resolution and you have a cached MX record from the last > time that the VPN was up, it is possible that you are chasing a name > that is different from what you expect. The transport address is static via a transport file. I'm wondering about the "type=AAAA", is postfix trying to resolve ip6 first? The remote host does not have a static ip6 address so an entry in /etc/hosts makes not sense. Anyway, no way to tell postfix that resolving a remote host is a temporary and not a permanent problem?
