Bug 364021

SMTP submission prints out stuff to stderr, so please:

1) ensure Trojita is not running,
2) start Trojita from console,
3) try sending e-mail as usual,
4) attach the log from console here,
5) reopen.

Common fails:
----
nb. that *web.de* like gmail.com recently requires you to allow acces via smtp (the defaults seemed to have been added randomly...)

For gmx, ensure to use the full mail address as login (tobias.leup...@gmx.de) and smtp.gmx.de:465
Most importantly do not mix TLDs, ie. smtp.gmx.net won't work for *.de logins et vv.

I thought port 465 was outdated and clients should use port 587? Just saying, with KMail, I use mail.gmx.net:587 with my @gmx.de address and it works just fine …

So here's what the console said:

With mail.gmx.net:587 and STARTTLS (which used to work just fine until recently), I get:

SMTP ** connectToHost
SMTP <<< 220 gmx.com (mrgmx102) Nemesis ESMTP Service ready
SMTP >>> "EHLO localhost\r\n"
SMTP <<< 250-gmx.com Hello localhost [87.171.206.252]
SMTP <<< 250-SIZE 69920427
SMTP <<< 250-AUTH LOGIN PLAIN
SMTP <<< 250 STARTTLS
SMTP >>> STARTTLS
SMTP <<< 220 OK
SMTP ** startClientEncruption
SMTP >>> "EHLO localhost\r\n"
SMTP <<< 250-gmx.com Hello localhost [87.171.206.252]
SMTP <<< 250-SIZE 69920427
SMTP <<< 250 AUTH LOGIN PLAIN
SMTP >>> AUTH PLAIN

and then, it hangs.

With mail.gmx.net:465, I can't even connect when using STARTTLS: only:

SMTP ** connectToHost

And a message "The remote host closed the connection".

With both mail.gmx.net:465 and mail.gmx.de:465 and TLS instead of STARTTLS, I get:

SMTP ** connectToHostEncrypted
SMTP >>> "EHLO localhost\r\n"
SMTP <<< 220 gmx.com (mrgmx102) Nemesis ESMTP Service ready
SMTP <<< 250-gmx.com Hello localhost [87.171.206.252]
SMTP <<< 250-SIZE 69920427
SMTP <<< 250 AUTH LOGIN PLAIN
SMTP >>> AUTH PLAIN

And it always hangs as described. So probably, the AUTH PLAIN step is what causes the trouble?

smtps is more robust than starttls (at least in the gmx.net case, because if anything goes wrong they fell back to the unencrypted variant which was oc. blocked ... ;-)

465 is smtps, so starttls will naturally fail.

That said, it fails. The server will timeout and afterwards you'll get:

SMTP <<< 334 421 gmx.com Service closing transmission channel - command timeout
SMTP <<< [authentication data]

Nuking AuthPlain in qwwsmtpclient.cpp (ie. enforcing LOGIN) works like a charm.
PLAIN authentication on gmail works like a charm.

=> gmx broke PLAIN authentication and it's unfortunately preferred by qwwsmtp.

Since LOGIN is announced first, kmail will likely just use that (for the order)
Seems to have been a problem on kmail around 2005 as well:
https://bugs.kde.org/show_bug.cgi?id=67797#c70


=> I guess it would be required to either allow config of the preferred authentication or prefer the announced order (what could be just as much troublesome) or walk them on each timeout (what's oc. outmost crap, sending a mail could easily last 10 minutes - every time!)

PS: src/qwwsmtp/qwwsmtp.cpp:553, make it

   if (false || s.toLower() == "plain")

this is oc. a terrible hack that will easily kill smtp servers only supporting PLAIN.

PPS:
the amount of "smtp gmx auth plain" on google results is just stunning...

(In reply to Thomas Lübking from comment #5)
> PS: src/qwwsmtp/qwwsmtp.cpp:553, make it
> 
>    if (false || s.toLower() == "plain")

false && ... shall work much better. it's too hot.

(In reply to Thomas Lübking from comment #4)
> gmx broke PLAIN authentication and it's unfortunately preferred by
> qwwsmtp.

Well, that sucks ;-) I fear that even if one contacted the GMX folks saying "Your server is broken", not much will happen … anyway, I'll try to do so.

Thanks for tracking this down. Would be nice if some solution (like configurable SMTP auth, fallback or something) could be implemented in Trojita, as sadly, not everybody respects standards like we can see here …

PLAIN is mantory by the standard, LOGIN is not even a "real" standard =)

GMX mandates the *optional* initial-response data (and mandate it to be the login data)
Sending "AUTH PLAIN =\r\n" gets me an immediate response about wrong credentials.
sending "AUTH PLAIN " and then calling setAuthPlain("<login>", "<passwort>"); works "as expected".

Apparently, GMX fixed it. At least, I can send mail again using the very same Trojitá versions ;-)

That's a pleasant surprise. Thanks :).