[Mailman-Users] A dumb first question

Mark Sapiro mark at msapiro.net
Thu Sep 29 20:16:20 CEST 2011

Laurie Lee wrote:

>My first question which may seem dumb for those of you with lots of
>If I create a 800 member Mailman list and send a single message to it, what
>will happen if the list is on  a Cpanel site with mail send restrictions of
>200 messages per hour?

It depends on a number of things.

There are installation-wide settings in Mailman that affect how
messages are sent. They can be sent as individual messages with one
recipient per message or as messages with perhaps as many as 500
recipients to one message.

In the best case, if the mail server accepts the first 200 recipients
and returns a temporary failure for the rest, Mailman will keep
retrying until the message is sent to all recipients.

In the worst case, Mailman will send a message with >200 recipients and
the mail server will reject all recipients. If the reject is a
permanent failure, this will result in 'bounces' for all recipients.
If the reject is a temporary failure, Mailman will keep trying, but
since the recipient list doesn't decrease, it will keep failing until
after up to 5 days, Mailman gives up and records 'bounces'.

There are other possible combinations in between.

Mark Sapiro <mark at msapiro.net>        The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan

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