I have problem with a mailserver and there is something I kind of not understand!
I can connect, authenticate, specify the sender address - but when specifying the reciever i get a error 550 which looks like so:
RCPT TO:email@example.com 550-DNSBL listed at zen.spamhaus.org 550 http://www.spamhaus.org/query/bl?ip=220.127.116.11
Now the strange thing is that 18.104.22.168 is my local client address. Not the servers ip address.
Also the error code 550 seems to be defined as so:
550 Requested action not taken: mailbox unavailable
To me that makes totally no sense. Why this error code with this spamhaus message? Why the local ip adress and not the servers?
There is exim running and there is nothing turning up in the logs mail.err mail.info mail.log mail.warn in /var/log
I looked up both the servers and the clients ip adress on blacklists. The clients ip adress is listed on some (as expected), but the server is totally clean.
Here is the complete telnet log when I reproduced the error. Mail clients like Evolution and Thunderbird give me the same spamhaus error message.
joe@joe-desktop:~$ telnet mail.hunsynth.org 25 Trying 22.214.171.124... Connected to mail.hunsynth.org. Escape character is '^]'. 220 hunsynth.org ESMTP Exim 4.69 Sat, 01 Jan 2011 17:52:45 +0100 HELP 214-Commands supported: 214 AUTH STARTTLS HELO EHLO MAIL RCPT DATA NOOP QUIT RSET HELP EHLO AUTH 250-hunsynth.org Hello chello062178015161.6.11.univie.teleweb.at [126.96.36.199] 250-SIZE 52428800 250-PIPELINING 250-AUTH PLAIN LOGIN CRAM-MD5 250-STARTTLS 250 HELP AUTH LOGIN 334 VXNlcm5hbWU6 dGVzdEBodW5zeW50aC5vcmc= 334 UGFzc3dvcmQ6 ***** 235 Authentication succeeded MAIL FROM:firstname.lastname@example.org 250 OK RCPT TO:email@example.com 550-DNSBL listed at zen.spamhaus.org 550 http://www.spamhaus.org/query/bl?ip=188.8.131.52 quit 221 hunsynth.org closing connection Connection closed by foreign host. joe@joe-desktop:~$
I tried the same thing from my other server and could successfully send an email.
So it really looks like the server does check the IP wich establiches the connection is in some blacklist.
This is theoretically a good thing - but - the authentication on the server should prevent that? Or shouldn't it?
Well I just think it would be absurd if I couldn't send email over my smtp server from my dynamic ISP connection because the dynamic is listed, altough i have a clean server with login?