|von Gagern » Martin » Bugs »||GMX|
I've got an account for Global Mail Exchange. It has repeatedly caused me problems, which in my opinion come from deficiencies in their server implementation. Most of these problems haven't been resolved to date.
Mails that were received via GMX get a
appended to all lines that start in
regardles of case. This is irritating while you read it, and can
invalidate digital signatures. There are storage formats that
require lines beginning with
this spelling to be escaped, but this is for storage only and should
be undone when a message is passed on.
The problem was filed as ID[|#1695324880#5134788#5bc0175#|] at
GMX. Later I got a mail with the new
ID[|#1695324880#5272077#5b6016f#|], stating that for some problem
no technical solution was possible. From the timing of this
message I have to assume they referred to the issue described here,
although enquiris to this effect remained unanswered.
Spam filters like SpamAssassin try to find
out from where a mail was sent, and treat mails from dynamic dial-up
addresses more likely as spam than mails from known legitimate mail
servers. Mails from authorized GMX customers should in this sense be
treated as originating from the GMX server. The fact that a user had
authenticated is noted in a header called
, but this is easy to fake and
ignored altogether by SpamAssassin.
SpamAssassin, on the other hand, looks
in detail at the
heraders. If one of
(Extended Simple Mail Transfer Protocol
Authenticated), that host will be held rsponsible for the
mail, and dial-up IPs on the way to this host will become
irrelevant. Sadly, GMX tags its mail only as
One would assume that adding two letters to a string shouldn't be too difficult, and that the servers would know whether or nor they are dealing with an authenticated user. The issue was forwarded to Tech Support according to ID[|#1695324880#4311007#5850161#|], and rejected in ID[|#1695324880#4468943#5df0177#|] due to the fact that the SpamAssassin installations rejecting the GMX mails due to this issue here were not the SpamAssassin maintained by GMX itself.
When you send a mail to a larger number of recipients, and one of
these addresses contains a wrong domain naime, GMX will send an error
message like this:
550 5.1.2 Cannot resolve your domain. Either
your mail user agent will tell you for which address it received that
error message, or it's up to you to check or try them one by one. In
the similar case of an invaliud recipient name with a GMX address, the
error message sent by GMX will contain the address causing this
The problem was filed as ID[|#1695324880#6391657#5d70176#|]. I received two mails supposedly on this issue, which both had nothing at all to do with my request. Instead I fixed the issue for my favorite MUA, Mozilla Thunderbird.
After entering a wrong passwort using the
command, and trying again with the legacy
command, the server used to terminate the connection upon receipt of
command, instead of asking for a password
and sending an error message if that was incorrect as
well. Incombination with a bug in
Thunderbird this could cause failure without any error message
when the password was wrong.
This issue has been resolved by GMX, and they even thanked me for the precise error description.