[Mailman-Users] Number of Recipients

Stephen J. Turnbull stephen at xemacs.org
Fri Jun 24 14:05:54 EDT 2016

Julian Kippels writes:

 > I have a question regarding the number of recipients per mail. If I have
 > a list with 50 entries, does mailman send one mail with 50 recipients,
 > or 50 mails with one recipient each?

That depends on your settings.  If your list is personalized (eg, has
links to the user's configuration page), then it will be one per
recipient.  Otherwise, it sends the mail in batches, how large depends
on the setting of SMTP_MAX_RECIPIENTS, which defaults to 500 or
something like that, much larger than your example of 50.

If the outgoing mail is batched, however, at some point (either in
Mailman or in the MTA, Mark will tell you if you need to know which)
the list will be grouped by addressee domain, and the message will be
sent once per domain.  (Possibly more times if you have a huge list.)

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