backing up users/Library/Mail/

[agarland]

My daily incremental backup includes backing up my users/Library/Mail folder. (I understand from Mail.app Help that this is what I should back up if I want to preserve my mailboxes, etc.) This part of my backup takes an inordinate amount of time, though--every night it backs up hundreds of megs of data, even though I receive only a handful of new emails every day that I keep (lots of junk mail, but I delete that immediately). Any ideas WHY an incremental backup of Mail takes so long, and what I can do to cut that time? Am using Retrospect 5.0.238, OS 10.3.2. Thanks!

[AmyJ]

I don't use that mail program, but I'm guessing that it works the same way that Outlook, and many other mail programs, work -- by storing all the mail in a single file. Each time you recieve a new piece of mail that file changes. The file may change size/dates even just by opening the program, and Retrospect is behaving properly by detecting those changes and backing the file up again.

 

For example, if the file (not folder) containing your mail is currently 250 megs, each time the file changes the whole 250 megs will be backed up again.

 

Outlook has a way to archive old mail - maybe your program can do the same thing. At least then your daily mail file may be more manageable, while your archive folder, which is infrequently updated, is not backed up daily.

 

Hopefully some users with more experience with OS X mail will chime in with some additional suggestions and correct me where I may be wrong in regard to how your program might work.

[shadowspawn]

To add a little to what Amy said, each mailbox in Mail.app is a separate file.

 

It can be very instructive to actually look at what contributed to the backup size. Open up the Contents Report and see what files actually hit the tape, and how big they were.

 

You might just have a lot of mail in various mailboxes, but two traps are the Trash and Sent mailboxes which have accumulating more mail than you expect.