Unfortunately, you cannot “convert” an existing POP3 account directly to an IMAP account. There is a simple three step process:
1. Remove your current POP3 account.
2. Add your new IMAP account.
3. Move all your mail to your new account.
Remove your current POP3 account
We strongly recommend you do a backup just in case something happens later on. How to back up your Outlook PST file.
Outlook 2003
Tools-> E-mail Accounts…-> button next-> select your POP3 account-> press Remove
Outlook 2007
Tools-> Account Settings…-> select your POP3 account-> press Remove
Outlook 2010, Outlook 2013 and Outlook 2016
File-> section Info-> Account Settings-> Account Settings…-> select your POP3 account-> press Remove
Add your IMAP account
Open your Accounting settings like you did above.
Click “New” or “Add new Account” and then “Manually configure server settings or additional server types”.
add account
Choose Pop or IMAP
account settings
Account Type: IMAP
Incoming mail server: mail.caprock-spur.com
Outgoing mail server: mail.caprock-spur.com
User Name: full email address
Check require logon using Secure Password Authentication (SPA)
Click More Settings
outgoing-server
Outgoing Server Tab
Check outgoing server (SMTP) requires authentication and use the same settings as my incoming server.
Advanced Tab
advanced-tab
Select Use the following type of encrypted connection and change to SSL
Incoming Server (IMAP) to port 993
Select Use the following type of encrypted connection and change to TLS
Outgoing Server (SMPTO) to port 587
Click OK.
Transfer your email folders and all your email from the old POP3 Account
Transferring email from your old POP3 account to your new account is simply click and drag the folders from your old account to your new account.
You cannot move or copy the Inbox or Sent Items folders since these are special folders. To move across these messages, you’ll have to select the messages and move them to the correct folder.