Warning on nearing mailbox size limit

[Peter Riocreux <par+postfix_users@xxxxxxxxxxxx>]

One of my colleagues whilst out of the office ran into a problem that
he received a lot of large attachments which caused his mailbox to
near the maximum size. He was unaware that things were bouncing at
some point after this as the bounce messages were not going into his
inbox, but sitting in the queue (as they should).

Is there some way to get postfix to send a user a mail when their
inbox is nearing its limit either when it exceeds a certain size
or proportion of total or when less than a minimum amount of space is
left?

Alternatively, can it be made to discount an amount of space needed
for such an informational message from the size of the mailbox and if
anything is bounced because of space, use this "reserved" space to
deliver the informational message?


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Peter