For it doesn't work.

This worked great! Worked for me on Mountain Lion 10.8.2. Huge speed boost!

I added this to my .zshrc file. Thanks!

Didn’t work for me:

➤ sqlite3 ~/Library/Mail/V2/MailData/Envelope\ Index vacuum;
SQL error: file is encrypted or is not a database

For whatever reason, I needed to modify the awk command to 'print $6' as the ls -lsh command puts the file size as the 6th column on the output, not the 5th. Not sure if that's just a typo at your end, or my end, or what....

In any case, thanks for this tip. Not sure yet if Mail.app will be any faster, but I did cut the size of the Envelope database by approx. 30%.

terrific improvement in responsiveness – Thanks a lot!

Thanks a ton for this great tip! I'm still running Lion and the path and command is the same.