Tips › Storage

Make your mail archive smaller on disk

5 October 2026 · searched as mail app using too much disk space

A mail archive grows with every attachment it keeps. MailCode shows what its archive takes, gives back space left behind by deleted mail, and lets you choose how much it keeps from here on.

How to do it

Open Settings ▸ Storage. Database size says how big the archive is and how much of it is free space.
Click Compact DB. MailCode says how long it will take, then writes a compacted copy and swaps it in — interrupting it costs nothing.
Remove copies you do not need with Find duplicates (everything).
For mail still to come, set Settings ▸ Sync ▸ Attachment downloads to When opened: attachments are fetched when you open them, not for every message.

MailCode: Settings ▸ Storage: the archive’s size, and what a compact would give back. — Settings ▸ Storage: the archive’s size, and what a compact would give back.

Compacting can only give back free space — attachments and message bodies are what an archive is, and they stay. Removing an account you no longer use deletes its mail from this computer, leaving the server alone. On Windows, older years can be moved out of the database into .eml files: right-click an archive folder ▸ Export … stored to .eml files….

MailCode is a mail client for Mac and Windows that keeps your mail in a searchable archive on your own disk. Free for 14 days.

Mac App Store Download for Windows