--On January 9, 2006 2:32:50 PM -0500 David Phillips <[log in to unmask]> 
wrote:

> We just recently upgraded to ListServ Classic, 14.4, and were hoping
> to take advantage of the Mail-merge features to put the subscribers'
> email address into our bottom banner.
>
> It works pretty well, except that one ISP is bouncing our messages.
>
> The only difference we can spot so far is in the Return-Path mail header.
>
> If Mail-merge=yes, the return path looks like
> this:Return-Path:<owner-saulnachem*skydaver**EARTHLINK*[log in to unmask]
> RG>
>
> If Mail-merge=no, the return path looks like this:
>    Return-Path: <[log in to unmask]>
>
> We'd really like to use the mail-merge (to catch AOLiens that report
> our list traffic as spam) but don't want to shut out our verizon.net
> members.
>
> Mail merge seems to really slow down processing, too.  We're using
> postfix as our MTA (I think that's the right term ... a different
> admin is handling that stuff)

Yup it will, because each message is a separate envelope, which is VERY 
expensive.  Normally it's batched in groups of 100 or more.

You're probably running afoul of sender validation.  There's no real fix 
since ListServ uses the non-standard * seperator rather than what everyone 
else uses (+ or sometimes =), however, if you use your postfix *ONLY* for 
ListServ you can change recipient_delimiter to * instead of +...I don't 
know if this accepts multiple chars or not, I haven't been able to try that.

I use a rewrite table on incoming mail to help map the * to + delimited 
addresses for delivery internally.