[MlMt] expiring deleted and sent

[Bill Cole]

On 8 Oct 2018, at 0:40, Randy Bush wrote:

>>> so, with the new hidden pref(s), anyone have a recipe for hard
>>> expunging sent and trashed messages> say 30 days?
>>
>> 2 different Smart Mailbox approaches:
>>   1. Mailboxes: Any of Sent, Trash;
>>      Conditions: Date is not within last 30 days;
>>      Rule: Conditions=[just exempting conditions]
>>            Action=Delete Permanently
>
> so when does it run this?

The *RULE* is run when a message is "added" to the Smart Mailbox, i.e. 
when a message in the source mailboxes meets the Smart Mailbox 
conditions.

How exactly MM notices the "addition" of messages to a Smart Mailbox 
isn't 100% clear, but I *think* it is triggered by appearance of new 
messages in IMAP mailboxes or changes in the metadata of existing 
messages that either MM does itself or is alerted to by the IMAP server 
during a sync operation.