Delayed expunge ON by default?

[Rob Mueller]

> My question: Did anybody using delayed expunge have any problem with it?

As the people (FastMail) who sponsored the development of this code, we've 
been using it for over a year now with no problems at all. It's been great. 
The performance improvement can be quite significant. Trying to empty a 
large folder with 10,000+ messages previouly could take minutes, now takes 
seconds. We then schedule the run of the cyr_expire process during our 
non-peak time.

Also it does allow much better backups. We schedule our incremental backups 
to run each day with a 2 day expiry time on the actual cyr_expire, which 
means apart from deleted folders, our backups include ALL messages that have 
ever passed through a users folders. David mentioned that his original 
expunge patches actually even allowed for the delete folder case (silently 
turned into a rename), which I think would be a nice future improvement so 
that you can guarantee a backup of every message, every day.

Rob