Hi, did anybody experience issues with Comcast blocking IPv6 addresses at SMTP level? We used to be able to send mail to comcast servers but since a couple of days they cancel SMTP connections with a misleading error message:
# telnet mx2.comcast.net. 25 Trying 2001:558:fe21:2a::6... Connected to mx2.comcast.net. Escape character is '^]'. 554 resimta-ch2-09v.sys.comcast.net comcast ESMTP server not available Connection closed by foreign host. Forward and reverse DNS etc. is all fine at our site. From other IPv6 subnets the SMTP connection isn't teminated. The KDE project had the same issues last year, see http://www.dslreports.com/forum/r29911000-E-mail-Wronly-Blacklisted-Email-System-or-Tech-Difficulties I already had a one hour call with a Comcast support guy but their support isn't helpful at all, in the end he didn't know what's wrong and the result of the call with them was zero. Currently it looks like Comcast needs to be IPv6 blacklisted for SMTP if you want to keep sending mails to them reliably. But that can't really shouldn't be the solution... Björn
