[Mailman-Users] ISPs and rDNS [was: Trouble with mailman external responses]

Mark Sapiro msapiro at value.net
Wed Mar 7 18:05:52 CET 2007

Barry Warsaw wrote:
>Which ISP do you use?  I have a static IP from my cable company but  
>they refuse to give me an rDNS entry.  In every other way, I really  
>like them, but I do get bounces occasionally from people's (IMHO)  
>misconfigured MTAs who don't accept mail from cable rDNSs.

I use value.net, now a part of amerion.com, but I don't recommend them.
My IP is a DSL connection from amerion.com, but it is via
dslextreme.com. I don't know the exact relationship between
amerion.com and dslextreme.com, but I have no specific problem with

Amerion.com is not too responsive. On the rDNS issue, I sent three
email requests to Amerion customer service over about 2 weeks. I got
no response to the first two. The third request was responded to with
"I've forwarded this to engineering" and the change was made a few
days later in only one of two name servers. One more email produced an
apology and an update of the second DNS a day or two later.

I also can't seem to get them to recognize that their MTA at
mail.value.net (Ipswitch Imail, aka SMTPD32, on a MS Windows box) is
seriously overloaded or misconfigured resulting in its often reaching
its maximum number of concurrent port 25 sessions which causes it to
stop listening and refuse a port 25 connect until something finishes.
I got so frustrated with connect refusals on my attempts to send mail
that I started using my own MTA. That ultimately solved my sending
problem, but not the issue of delayed and out of sequence incoming
mail. (Actually, I think they've done something as the situation isn't
as bad as it once was, but it's still a problem).

People see/hear this rant and ask why I just don't go somewhere else,
and I have no good answer - just inertia and an attachment to my
value.net address.

Paul Tomblin wrote:

>The biggest problem I had when I was doing a mailman list on my home
>server was that many sites would refuse email from IPs that were on their
>RBLs list of dynamic IPs.  Yes, some of them look for a valid rDNS, but
>99.99% of them were perfectly happy with an rDNS of
>"74-202-84-132.static.twtelecom.net" rather than "list.xcski.com".

Actually, when I first started using my own MTA, I just configured the
MTA's primary host name as netblock-68-183-193-239.dslextreme.com, and
things worked well except for earthlink.net. I don't know if they
would have liked me better if the name had been
netblock-68-183-193-239.static.dslextreme.com, but I wound up going
through the whole domain registration/rDNS dance before I could get
them to unblock me.

Mark Sapiro <msapiro at value.net>       The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan

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