debug SMTP commands sent/received to/from the submission service

[Plutocrat]

On 09/04/2021 15.13, Victor Sudakov wrote:
> I'd use Wireshark but the communication between SMTP clients and Dovecot is encrypted
> after STARTTLS, so Wireshark is pretty useless here.

You might get some useful information connecting with openssl s_client

Here's a page googled at random.
https://halon.io/blog/how-to-test-smtp-servers-using-the-command-line/

And man page.
https://linux.die.net/man/1/s_client

P