Mail delivery failed because of VPN

  • 1 July 2021
  • 2 replies

Most of my emails aren’t send anymore. I got this reply:


Mail delivery failed: returning message to sender>

>This message was created automatically by mail delivery software.>

>A message that you sent could not be delivered to one or more of its

>recipients. This is a permanent error.>

>The following address failed: ...t-online.de


The support of my provider told me, that my IP address (be sent over VPN) are marked as spam because it is on 4 black lists.

>--- The header of the original message is following. ---


>X-Spam-Flag: YES




What should I do?

2 replies

Userlevel 7
Badge +8

@g.gloeckner Welcome.

Your ISP Smtp  server can’t probably not  identify your E-Mail domain and is blocking your outgoing messages.

Please exit VPN and try again ?

Webmail should be no problem.



I can send e-mails if I exit VPN and it fails sending as soon as I start it again.