Normally, emails are sent as they are created. This behavior can be changed,
and the Message center provides a page which allows you to manually request that
the queued messages be sent. This is in case the automatic processes are not
set to send an important message quick enough.
There are a few parameters in the system configuration which control
the operation of the sending portion of the Message center.
- queue_min - This parameters controls how 'old' a message should be
before it is sent. The default is 0 minutes, so messages are eligable to be
sent as soon as they are queued. Message center is smart enough to combine
multiple messages to the same person into one email. For a busy site, this
can cut down the number of emails that an administrator needs to deal with.
- multiple_msg_subject - This parameter just supplies a "standard"
subject line for an email that is a combination of messages.
- runqueue - This parameter controls when the queue is checked to
see if there are messages to be sent. The default (YES) means that the queue
is checked during the processing of each login. In a milding active site,
this should be frequently enough to keep messages moving. In a very active
site, or there are a lot a emails that are queued, this operation could slow
down login, so it can be changed to NO. If it is set to NO, emails will only
be sent on a manual request, or through a cron job on the host system which
requests that they be sent.