---
id: troubleshooting.mail-cant-be-moved-while-open
url: https://storagestudio.us/faq/troubleshooting/mail-cant-be-moved-while-open
category: "Troubleshooting & messages"
subcategory: "Moves and copies that didn't finish"
question: "Why does it say Mail changes these files constantly, so they can't be moved?"
alt_questions:
  - "mail changes these files constantly while it's open"
  - "can't move mail folder storage studio"
  - "move mail data to external drive"
  - "mail downloads can't be moved"
short_answer: "Mail rewrites its data constantly while it's open, so moving it then could corrupt your mailbox. Quit Mail completely and try again."
tags: ["mail", "in use"]
related: ["https://storagestudio.us/faq/troubleshooting/folder-in-use-right-now", "https://storagestudio.us/faq/troubleshooting/app-private-area-wont-be-moved"]
applies_to: "all"
last_reviewed: 2026-10-01
---

# Why does it say Mail changes these files constantly, so they can't be moved?

Mail rewrites its data almost continuously while it's open, so moving it out from under Mail could corrupt your mailbox. Storage Studio won't do it while Mail is running.

### What to do
Quit Mail completely, then try again. If Mail is set to open at login or reopens itself, quit it right before you start the move.