---
id: mac-storage-basics.why-is-apple-mail-using-so-much-space
url: https://storagestudio.us/faq/mac-storage-basics/why-is-apple-mail-using-so-much-space
category: "Mac storage basics"
subcategory: "Mail, Messages and chat apps"
question: "Why is Apple Mail using so much space on my Mac?"
alt_questions:
  - "mail storage huge mac"
  - "mail app taking gigabytes"
  - "reduce mail storage macos"
  - "mail folder size mac"
  - "apple mail library too big"
short_answer: "Mail stores local copies of messages and attachments, plus opened attachments in Mail Downloads. Delete big old messages, erase deleted items, and limit attachment downloads."
tags: ["mail", "attachments", "library"]
related: ["https://storagestudio.us/faq/mac-storage-basics/how-do-i-stop-mail-downloading-attachments", "https://storagestudio.us/faq/mac-storage-basics/where-are-mail-downloads-stored"]
applies_to: "all"
last_reviewed: 2026-10-01
---

# Why is Apple Mail using so much space on my Mac?

Mail keeps a local copy of your messages and, depending on settings, their attachments, so large or long-lived accounts add up. Attachments you've opened are also saved in a separate **Mail Downloads** folder.

Ways to shrink it:

- Delete large old messages, then **Mailbox → Erase Deleted Items**.
- Limit attachment downloads for IMAP accounts (see [attachments setting](https://storagestudio.us/faq/mac-storage-basics/how-do-i-stop-mail-downloading-attachments)).
- Remove accounts you no longer use from the Mac.
- Clear old files from Mail Downloads.

Storage Studio's What's Using Space shows the Mail library's size and the Mail Downloads leftovers separately.