On Sun, Mar 04, 2012 at 04:24:44PM +0100, Stanisław Findeisen wrote: > On 2012-03-04 11:26, Michael Tokarev wrote: > > On 04.03.2012 13:30, Stanisław Findeisen wrote: > >> On 2012-03-04 09:20, Stanisław Findeisen wrote: > >>> I am running a small Postfix server, and for a couple of hours > >>> I've been getting: "host ... refused to talk to me: 421 service > >>> not available (connection refused, too many connections)" for > >>> all the outgoing mail, all destination servers. > >>> > >>> What's wrong? > >>> > >>> I wasn't even able to subscribe to this mailing list: > >>> > >>> Mar 4 00:41:38 k8ux postfix/smtp[2987]: 1462B1F2505: > >>> to=<majord...@postfix.org>, > >>> relay=mail.cloud9.net[168.100.1.7]:25, delay=417, > >>> delays=417/0.02/0.06/0, dsn=4.0.0, status=deferred (host > >>> mail.cloud9.net[168.100.1.7] refused to talk to me: 421 service > >>> not available (connection refused, too many connections)) > > > > This smells very much like your outgoing SMTP connections are > > being trapped by your ISP and redirected to _their_ SMTP server. > > Wha... what a... ??! 8-O > > You say that mail.cloud9.net[168.100.1.7] was in reality my ISP's > network node? I.e., they are doing some kind of man in the middle > attack / IP address spoofing?
Respectively: no, sort of, and no. mail.cloud9.net is still on its own IP address, as are the other hosts you tried. It looks like transparent redirection. > Why do you think they should be doing crap like that??! Controlling/limiting outbound abuse in case of spammers on their networks ... this is my guess. But I don't work for your ISP. > It just started to work after some 15 hours or so. ALL > destination servers (the whole queue has been sent out). Given this additional information, it looks like you triggered an automated rate limiting system in the ISP firewall. Review your terms of service and acceptable use policy. Ensure that you're in compliance. Then, talk to the ISP and ask them about it. -- http://rob0.nodns4.us/ -- system administration and consulting Offlist GMX mail is seen only if "/dev/rob0" is in the Subject:
