dovecot warns (non-fatal) "invalid EHLO response line: Unexpected character in EHLO keyword" connecting to submission relay ?

[@lbutlr]

On 26 Sep 2020, at 07:45, Alec Moskvin <alecm at gmx.com> wrote:
>    250-AUTH PLAIN LOGIN
>    250 AUTH=PLAIN LOGIN

I believe this is not really an issue. The warning is just that, a warning. Some (broken) mail clients, Immagonnaguess Microsoft ones, expected the =, so many mail servers provide it.

AFAIK, It is safe to ignore the warning.

Ah, yes, I think this is it? (At least for Postfix)

<http://www.postfix.org/SASL_README.html>
> broken_sasl_auth_clients (default: no)
> Enable interoperability with remote SMTP clients that implement an obsolete version of the AUTH command (RFC 4954). Examples of such clients are MicroSoft Outlook Express version 4 and MicroSoft Exchange version 5.0.
> 
> Specify "broken_sasl_auth_clients = yes" to have Postfix advertise AUTH support in a non-standard way.


It is probably safe for anyone to disable that, however, as I don't think those old versions support modern TLS.


-- 
showing snuffy is when Sesame Street jumped the shark