Maclord's Blog

If you’re a heavy user of Apple Mail.app, you may find that over time the program takes longer and longer to open, and operates more and more sluggishly.

There’s a trick to making things faster, one that never fails to work. Open Terminal and run the following command:

sqlite3 ~/Library/Mail/Envelope\ Index vacuum

This command basically cleans old and discarded crud out of the database that Mail
uses to keep track of messages. When old messages are deleted, Mail unfortunately
keeps some information about them around, and that’s what you’re nuking from orbit.
Here’s an example on my machine that shows the before and after

$ cd ~/Library/Mail
$ ls -l
-rw-r--r-- 1 maclord staff 61M Feb 15 23:14 Envelope Index
$ sqlite3 ~/Library/Mail/Envelope\ Index vacuum
$ ls -l
-rw-r--r-- 1 maclord staff 33M Feb 16 18:35 Envelope Index

If you would run it often on the Terminal, make an alias for it, either in .bashrc or
.bash_aliases

alias vacuummail=‘sqlite3 ~/Library/Mail/Envelope\ Index vacuum’

If you’re really feeling ambitious, you could create an Automator action that would shut
down Mail, run the command, and start Mail back up. You could even make it an iCal Alarm and set it to
run once a week, and you will guarantee that Mail runs lean and mean. Or, if you don’t
like Automator, use a tool like Lingon to run the command for you at a set time.

P.S. These methods have been tested with Mac OS X (10.6) Snow Leopard – untested with Lion (OS X 10.7)