[MlMt] Changing the default source mailbox for smart folders

[Tim April]

Hello,

I’m fairly new to MailMate (downloaded last week at the suggestion of 
some friends). I am working to setup all of my smart folders in a way 
that works for me and I keep running into an issue where the application 
freezes for multiple minutes when creating a new Smart Mailbox. I 
believe that the cause is the default source mailbox is “All 
Messages”, which in my case is ~1M messages right now. Running into 
this issue often, I have found myself searching a couple times for a way 
to switch the default source for smart mailboxes, or to delay processing 
of the changes until I save.

Am I missing a hidden preference or work around that I have not been 
able to uncover using google?

Thanks,

--tim