How to stop Outlook downloading files to my Mac

Question

Hello,

I use Legacy Outlook on my Mac for my work emails.

Every few months I have to delete Outlook and all it's files it downloads to my laptop as my system storage is completely full.

I have googled how to stop this from happening but all the options it gives me do not work.

Please can someone let me know how to stop Outlook from downloading all this data to my Mac?

Thanks

Answer 1

Hi Clare

Thank you for reaching out to the Q&A Forum.

You can first try the answer provided by Q&A Assist, and could you please share how it goes?

I would like to share some recommendations from my research that I hope will be helpful.

Switch to "New Outlook for Mac"

From my understanding, the "New Outlook" uses Microsoft Cloud sync technology. It does not store a large local database on your hard drive. Instead, it caches only what is necessary, which drastically reduces storage usage. You can try switching to New Outlook to see if this helps.

Download "Headers Only"

If you need to stay on the Legacy version for specific workflow reasons, you can try limiting what Outlook downloads.

• Open Outlook > Go to Tools > Accounts
• Select your business account > Click Advanced

Look for an option that says "Download headers only" (Note: Depending on your specific Exchange/Office 365 license, this option may be disabled or grayed out. If available, enabling it will stop Outlook from automatically downloading full attachments until you click them).

Clear Cache Instead of Reinstalling

You do not need to delete the entire Outlook application to free up space. You can clear the cache of specific heavy folders (like Inbox or Sent Items).

• Right-click (or Control-click) on a folder (ex: Inbox) > Select Properties > Click Empty Cache

This will wipe the local copy, and Outlook will then re-download only the most recent items, temporarily freeing up space.

Additionally, if you try deleting the profile data only (as Q&A Assist recommended), please note that if you have data stored under "On My Computer" (local folders not synced to the server), deleting this profile will permanently delete that data. Make sure you only do this if all your mail is stored on the Exchange server.

I hope this information helps, and I look forward to your response.

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Answer 2

To stop Outlook from downloading files to your Mac, you can adjust the settings related to cached data and shared folders. Here are some steps you can take:

1. Disable Cached Exchange Mode: If you are using Outlook with an Exchange account, you can disable Cached Exchange Mode. This will prevent Outlook from storing a local copy of your emails and attachments. You can find this option in the account settings under the advanced settings for your Exchange account.
2. Manage Shared Mail Folders: If you have shared mail folders that are being downloaded, you can manage the download settings for these folders. Ensure that the option to download shared folders is disabled, which can help reduce the amount of data being stored locally.
3. Regularly Clear Cache: You can periodically clear the cache and temporary files that Outlook uses. This can be done by quitting Outlook and deleting the contents of the cache folders located in ~/Library/Group Containers/UBF8T346G9.Office/Outlook/Outlook 15 Profiles for Outlook 2016 for Mac or ~/Documents/Microsoft User Data/Office 2011 Identities for Outlook 2011.
4. Limit Attachments: Be mindful of the attachments you download. If possible, avoid downloading large attachments or save them directly to an external drive instead of your local storage.

By following these steps, you should be able to manage and reduce the amount of data Outlook downloads to your Mac, helping to keep your system storage from filling up too quickly.

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References:

• Outlook for Mac is a locally cached email client
• Manage download settings for shared mail folders in Cached Exchange mode in Outlook