For Thunderbird users, if you’re running out of space, or just before you run a defrag on your hard drive, you can free up some additional space using Thunderbird’s Compact Folders command. I ran it just now and my inbox folder size dropped from 600mb to 300mb!
Basically, when you delete files from Thunderbird, it goes to Trash. And when you empty the trash, Thunderbird doesn’t really purge the files, instead it only hides it from you. What? It doesn’t? Yeah, you heard me right, Thunderbird hides the deleted emails from you, together with the deleted attachments. If you’re wondering why you’ve been doing housekeeping on your emails all these while and your mail folder size doesn’t get any smaller, now you know.
Run Compact Folder will force Thunderbird to housekeep itself, purge all those deleted emails, and compress the mail file.
If you have multiple accounts set up, you’ll need to do it for each, individually.
Here’s how you do it:
![]() |

Thanks for the info. I don’t really use thunderbird but some of my friends do. I’ll try to tell them about this. Thanks again.