[Mailman-Users] Too many recipients

[Stephen J. Turnbull]

Rodrigo Abrantes Antunes writes:

 > Searching google I found that this error isn't related to the number of
 > users in the list, it occurs because the total number of addresses in the
 > To: and Cc: headers of the post equals or exceeds
 > max_num_recipients.

The operational issues have already been addressed well in other
posts.  However the above statement is incorrect, and needs
clarification.

The items visible in your personal mail client (MUA) in the To:, Cc:,
and Bcc: fields are usually called "addresses" or "addressees".  These
are different from "recipients", which are the addresses that the
host-to-host mail program (MTA) sends to.  Mailman "explodes" the
list's *address* into a large number of *recipients*, and asks the MTA
to deliver to that whole list of recipients, or to chunks of it as
Mark explains elsewhere.  You will in general never see the list of
recipients of a post unless you look at the MTA's logs.

By the way, there's nothing wrong with your understanding of plain
English, in which "address" and "recipient" are pretty much the same.
However, in technical discussion these words are often distinguished
as above.

 > But in documentation is said that if this option is set to 0 it has
 > no limit.

The limit you are running into here is not in Mailman, it is in the
MTA.  Mailman cannot tell the MTA what to do; it can only restrict
itself to a small enough number that the MTA will cooperate with it.