I’m facing a problem with sending email from our website.
Sending e-mail from clients like thunderbird works fine.
Currently we have dockers running for each website on the same server as we host our dockerized mailcow.
Structure is as follows:
- Mailcow docker
- Website 1 docker
- Website 2 docker
nginx as reverse proxy to redirect website domains to the correct docker port
All mail is handled by mailcow with (almost) default configuration, so no other mail software is running on the server. When I want to send an e-mail from for example “Website 1” via SMTP, I get the following error message:
cannot connect to host; error = stream_socket_client(): unable to connect to tcp://<the mail hostname>:587 (Connection timed out) (errno = 0 )
I tried different settings, ports, authentication etc.