Re: [exim] Problem sending Mail to comcast

Tom Fischer wrote:
> i have much trouble sending to comcast Mailservers. The comcast Servers
> returns "450 [TEMPFAIL] comcast.net requires valid sender domain".

So, what domain does the envelope-from have on a typical mail
that gets rejected? Does that domain exist, have proper rDNS
and matching forward DNS?

> Sometimes the mail goes thru after a few hours but mostly not.

Is your DNS provider unreliable?

> What i
> can see with ngrep

ngrep of what?

> is that my exim must wait a long time for Return
> Messages and then send line to the comcast servers like this
>
> "From:<xyz@???> To:<xyz@???> ..."

Please, don't obfuscate. It makes it hard for us to help you.
Post a complete log segment of a failing transaction.

> and does not wait for return code, so comacst servers saw the To-Header
> not correctly.

Unlikely to be the headers (the 822 addresses). More likely
to be the envelope (the 821 addresses, specifically the From).

> I think that the problem is on comcast Side but how to
> explain my customers.

I suspect not.

- Jeremy