Queued outgoing mail

[Tim Gray]

Is there a method for queuing outgoing mail?  Eudora used to have a feature 
where you could queue sent mail for deliver at either a specified time, or 
after a specified delay (ex. 10 mins from now).  Is there anyway to do this 
with mutt?  I'm currently using postfix as my smtp delivery agent if that 
makes a difference.

On a related note, if I send an email while I'm offline, it goes into the 
postfix queue fine.  How/when does postfix flush that email out?