In message <200005091436 .
"Bernie Cosell" <bernie @
>Apologies for another off-topic inquiry, but again you folks probably
>have thought about this kind of thing more than any other forum I can
>Is there a good rule-of-thumb for what to set the MaxRecipients pamarater
>to in sendmail?
I seem to vaguely recall that there is something somewhere in one of
the relevant RFCs that says something to the effect that MTAs should
be able to handle _at least_ 100. (This perhaps explains why the
default value implemented by sendmail is 100.)
>And the meta question: what happens to the sending server if the limit is
>exceeded... are the servers clever enough to requeue the message and then
>send, later, another 'chunk',
If by ``server'' you mean Sendmail, then the answer is `no'. It is
very simple. If you have MaxRecipients set to `N' and then some SMTP
client connects and tries to issue more than `N' RCPT TOs for some
individual message, then the N+1 and subsequent RCPT Tos will get some
sort of 5xx response.
> or will the original sender (probably an
>MLM) just get back an error.... [of course, if the limit is anything more
>than, say, 10 or so, about the only thing that could bust the limit is if
>a LOT of our customers subscribe to a particular mailing list and so we
>get mail from that MLM's server addressed to a boatload of our users]
If you set MaxRecipients to (say) 10, and then *you* try to send an out-
going e-mail to eleven of your closest friends, you may experience a
problem. Obviously, it depends on what MUA you are using.
I have tried setting MaxRecipients down to some low number in the past
(in order to thwart spammers... or at least to slow them down) and I
quickly found out that (at least with the MUA I have been using... i.e.
the Rand/UCI MH package) I had effectively limited the number of recipients
that _I_ could address one of my own outgoing messages to.