You may want to download your emails to Outlook but also keep a copy on your mail server. This is common when you check the same account from multiple devices or want a webmail backup. By default, Outlook’s IMAP settings can delete messages from the server after a set period. This article explains how to change the account settings to ensure emails remain on the server after you download them to your computer.
Key Takeaways: Keep IMAP Emails on Your Server
- File > Account Settings > Server Settings > More Settings > Advanced: Controls the deletion policy for messages on the IMAP server.
- Advanced tab > Deleted Items: The checkbox here determines if Outlook removes emails from the server when you delete them locally.
- Advanced tab > Root folder path: An incorrect path here can cause Outlook to use a different server folder, affecting sync and retention.
Understanding IMAP Server Retention in Outlook
IMAP is a protocol designed to synchronize email between a server and your devices. Unlike POP3, it typically keeps messages on the server by default. However, Outlook adds its own layer of settings that can override this behavior. The primary control is found in the account’s advanced settings, where you manage how long to keep items and what happens when you delete them in Outlook.
A common point of confusion is the difference between removing an email from your local view and removing it from the server. When you delete an email in your Outlook inbox, the client can be configured to either just hide it locally or to also send a command to delete it from the server. The goal of keeping emails on the server is to ensure all your devices see the same, complete mailbox.
Prerequisites for Configuration
Before you start, confirm your email account is set up as an IMAP account in Outlook, not POP3. You will also need to know your mail server’s incoming and outgoing settings, though you usually only need these for initial setup. The changes you make only affect the Outlook profile you are currently using. Other devices or email clients will have their own separate settings.
Steps to Change Your IMAP Retention Settings
Follow these steps to adjust your Outlook configuration so emails stay on the server after download. The exact dialog titles may vary slightly between Outlook for Microsoft 365, Outlook 2021, and Outlook 2019, but the path is the same.
- Open Account Settings
In Outlook, click the File tab in the top-left corner. In the Account Information screen, click the Account Settings button, then select Account Settings again from the dropdown menu. - Select Your IMAP Account
The Account Settings window will open. On the Email tab, click to select your IMAP email account from the list. Then, click the Change button located above the list. - Access More Server Settings
The Change Account window shows your basic server information. Click the More Settings button in the lower-right corner of this window. - Navigate to the Advanced Tab
A new Internet Email Settings window will open. Click on the Advanced tab at the top. - Configure the Deletion Settings
In the Advanced tab, find the section labeled Delivery. Ensure the box for Leave a copy of messages on the server is checked. Also, look for the option under Deleted Items. Uncheck the box that says Purge items when switching folders while online. This prevents automatic cleanup. - Apply and Close
Click OK to close the Internet Email Settings window. Click Next in the Change Account window, and then click Finish. Close the Account Settings window. You may need to restart Outlook for the settings to take full effect.
Common Mistakes and Limitations to Avoid
Emails Still Disappear from the Server
If emails are still being removed, check another setting. In the same Advanced tab, look for the option Remove from server after [X] days. If this is checked, Outlook will delete messages from the server after the specified period, even if the main copy setting is on. For permanent retention, uncheck this box entirely.
Using the Wrong Root Folder Path
An incorrect Root folder path can cause Outlook to sync with a non-standard folder on the server, like a hidden archive. This can make it seem like emails are missing. For most providers, this field should be left blank. For some, like Gmail, you may need to enter “[Gmail]” as the path. Check your provider’s documentation.
Server Storage Limits
Keeping all emails on the server indefinitely will use your allotted server storage space. If your mailbox becomes full, you may stop receiving new emails. You must periodically log into webmail or use another client to archive or delete old messages to free up space. Outlook cannot manage server storage limits for you.
IMAP Retention Settings Comparison
| Item | Keep on Server (Recommended for Multi‑Device Use) | Remove from Server (Default for Some Setups) |
|---|---|---|
| Primary Purpose | Sync mailbox across phone, laptop, and webmail | Download emails to one computer only |
| Server Storage Use | High, requires manual management | Low, emails are moved off the server |
| Deleted Item Behavior | Deleting in Outlook can be set to only hide locally | Deleting in Outlook typically removes from server |
| Best For | Users who access email from multiple locations | Single-computer users who back up emails locally |
| Outlook Setting | Leave a copy of messages on the server checked | Leave a copy of messages on the server unchecked |
You can now use Outlook on your computer while keeping a complete copy of your emails on your provider’s server. This ensures your phone, tablet, and webmail interface stay in sync. For advanced management, explore creating Outlook rules to automatically move old messages from the server to a local archive folder. Remember to periodically check your server storage via webmail to avoid hitting your account’s limit.