On Wed, 2021-10-20 at 19:27 +0200, Claus R. Wickinghoff wrote: > Hi, > > > In summary, postfix mail works fine if VPN if off, does not work if > > VPN > > is on, any advice would be appreciated, thanks DAN > > So postfix is not the issue, but vpn is. :-) > > You can configure a vpn to route all traffic into the tunnel. A valid > configuration for branch offices or roadwarriors so no malware can > forward internet traffic through a vpn into a company network. > > I propose to investigate further into this direction. > > Groetjes > Claus > >
Hey! I have exactly the same problem. I have two personal servers I run for two different groups, one with exim and one with postfix. I use ProtonVPN and Mullvad as VPNs on my laptop. When I have either vpn running, mail works fine through my exim box and hangs sending to my postfix box. I'm running kubuntu on my laptop: $uname -a Linux n1 5.11.0-37-generic #41-Ubuntu SMP Mon Sep 20 16:39:20 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux I use evolution as my mail client on the laptop. Here's the note from /var/log/mail.log on my postfix server: Oct 20 20:07:49 libertyfp postfix/smtpd[174025]: warning: hostname ip245.tervelnet.com does not resolve to address 87.246.7.245 Oct 20 20:07:49 libertyfp postfix/smtpd[174025]: connect from unknown[87.246.7.245] Oct 20 20:07:51 libertyfp postfix/smtpd[174025]: warning: unknown[87.246.7.245]: SASL LOGIN authentication failed: UGFzc3dvcmQ6 Oct 20 20:07:51 libertyfp postfix/smtpd[174025]: disconnect from unknown[87.246.7.245] ehlo=1 auth=0/1 rset=1 quit=1 commands=3/4 Oct 20 20:09:35 libertyfp postfix/smtpd[174449]: warning: hostname ip245.tervelnet.com does not resolve to address 87.246.7.245 Oct 20 20:09:35 libertyfp postfix/smtpd[174449]: connect from unknown[87.246.7.245] Oct 20 20:09:37 libertyfp postfix/smtpd[174449]: warning: unknown[87.246.7.245]: SASL LOGIN authentication failed: UGFzc3dvcmQ6 Oct 20 20:09:37 libertyfp postfix/smtpd[174449]: disconnect from unknown[87.246.7.245] ehlo=1 auth=0/1 rset=1 quit=1 commands=3/4 87.246.7.245 is the address the vpn is using (in Bulgaria) and a web utility like "whatismyipaddress.com" resolves it to ip245.tervelnet.com However, nslookup and dig on my laptop do not resolve it: %nslookup ip245.tervelnet.com Server: 127.0.0.53 Address: 127.0.0.53#53 ** server can't find ip245.tervelnet.com: NXDOMAIN > server 8.8.8.8 Default server: 8.8.8.8 Address: 8.8.8.8#53 > ip245.tervelnet.com Server: 8.8.8.8 Address: 8.8.8.8#53 ** server can't find ip245.tervelnet.com: NXDOMAIN
