On Thu, 29 Dec 2005 15:36:44 -0600, Winship <[log in to unmask]> wrote:

>   ----- The following addresses had permanent fatal errors -----
><[log in to unmask]>
>    (reason: 451 4.1.8 Domain of sender address [log in to unmask] does not
>resolve)

LOC's mail server is doing a reverse DNS lookup on your domain (ccsi.com) to
verify that it exists before deciding to accept the incoming email.  This is
very common nowadays, usually as an anti-spam measure.  However, for some
reason (faulty DNS records or faulty DNS server lookup recursion, or ...)
this lookup fails.  Since the LOC mail server doesn't get a valid response
it refuses to accept your incoming email.

My check of ccsi.com returns a valid DNS lookup so I suspect that LOC's DNS
server is hosed.  But I also recall from an earlier email from you that
ccsi.com DNS records were also hosed a couple of weeks ago, so maybe LOC
placed this domain on a local blacklist of some kind and is not actually
using current DNS to perform its check.

All of this trouble suggests that it is important these days for a List
Owner to have access to an auxiliary email address (even hotmail/yahoo/gmail
would be OK for this) and have their list pre-configured for this auxiliary
email address (both for List Owner access and for msg posting) to be able to
work around such "helpful" mail blockages.  Unfortunately these blockaages
are becoming extremely common.  :-(

Yes, it is inconvenient for List Owners, and can be a real PITA but the
alternative is to have your list stop working completely which is probably
worse.