"LISTSERV site administrators' forum" <[log in to unmask]>
wrote on 04/14/2004 12:14:41 PM:

> Is there a global setting (or individual list setting) that would only
send
> the message out once.  In other words, if there is a connection problem
with
> an outside mail host or any other issues, it will not retry.
>

That would be a very bad idea and guarantee that you would not be able to
deliver email to me.  We use a spam filtering technique called
greylisting.  The first time you attempt to deliver mail to my server, it
will issue a temporary failure code.  When you try again, the system will
then accept the message.

Besides, your idea is in violation of the RFCs for email.