[imp] disable attachment cleanup

[Gary Smith]

> You need to set the following in your prefs.php of imp.
> 
> $_prefs['delete_attachments_monthly'] 's value to 0.  This will be
> effective for more than 6 months option.
> 

I didn't think about looking into the prefs file.  Anyway, thanks for the pointer.

This leads to another question.  The prefGroups['logintasks'] contains several things like delete sent mail, etc.  If I remove it from there, does it kill the task for all users (which is what  I want to accomplish)?

Gary-