outlook imap can not be enabled on web setting , the save button lose efficacy on web setting

Hi! Thank you for the information. You've completed the basic troubleshooting for this issue, at this point there are only two possible issue left:

1. Account restriction. a. If your Outlook account is tied to a work or school/ University Microsoft 365 account, the system admin more likely disabled IMAP. b. In this case, the toggle appears, but clicking Save never applies because the setting is blocked by policy.
2. Outlook.com service bug

• Sometimes, for personal Outlook.com, the IMAP toggle page is broken. Microsoft has acknowledged this in the past, and the workaround was to change the setting via PowerShell

Let me know if the your case is not due to account type so you can proceed with the troubleshooting via PowerShell

Thankyou for confirming the details. The “Save” button not working is normal here, since your setting is already saved (IMAP is enabled). If you want to confirm if IMAP is working you need to check and add your account to an email application. Use these settings for IMAP:

• IMAP server: outlook.office365.com
• Port: 993
• Encryption: SSL/TLS
• SMTP server: smtp.office365.com
• Port: 587
• Encryption: STARTTLS

If you have 2-step verification enabled on your Microsoft account, you’ll need to create an App password instead of your normal password: