An email folder with almost 60,000 files strikes me as rather big. It takes up almost 2 gigs on my HD. One of the folder options allows compressing it.
Does compressing files slow access much?
Are there any good utilities to compress it even more?
OR, can I transfer to my secondary HD, and have my system access it from there?
Are you implying the OP should go through all 59,000 emails and pick out the ones he/she wants to keep?
Anyway, to the OP: you probably want to tell us what the e-mail client and operating system you use. And if the reason for asking is because your primary HDD is running out of space, can’t you just move the entire mail data to the secondary HDD?
They have boosted it in recent versions, but for normal folks, 2 GB is the absolute maximum size for an Outlook mailbox or .pst file. The default warning that the file’s getting too big is about 1.8 GB, and at 2, it shuts off. You’re also limited to about 65,000 items in the file. Either way, you’re far too close to the maximums for comfort.
There is a registry edit that allows you to have 20 GB pst files, but I don’t know if that also boosts the number of items that can be in the file.
You really should stay smaller - where I’m at, we don’t allow server-based mailboxes over 100 MB, and strongly suggest pst files be kept under 50 MB. The database file that’s the core of a pst tends to get a little wonky past a certain point. Plus, smaller pst files means smaller risk of loss in case a file does go bad. There is a pst repair tool, but it’s almost guaranteed not to work on anything much bigger than 50 MB.
Compressing once in a while is a good idea - it’s much like doing a disk defrag and helps maintain the database structure.