IMAP Protocol

Hello, @Roger Roger,

Welcome to the Microsoft Q&A platform!

Although IMAP offers the flexibility of accessing email through multiple devices, it carries a variety of security risks. For instance, it is susceptible to IMAP injection and credential stuffing attacks that can bypass multi-factor authentication and result in unauthorized access. Additionally, if not properly encrypted, data transmitted via IMAP can be intercepted, and even with encryption, management risks remain.

IMAP relies on basic authentication, making it vulnerable to brute force and phishing attacks. As a legacy protocol, IMAP is less secure than modern email protocols, and disabling it helps reduce the attack surface. Organizations needing to comply with regulations also face challenges in ensuring compliance and security auditing when using IMAP.

More secure alternatives, such as Microsoft Exchange ActiveSync or web access through a secure browser, offer stronger security features like modern authentication and data encryption. Prioritizing these more secure methods can effectively reduce security risks while still meeting users' email access needs.

If you do need to enable IMAP, it is advisable for you to follow the reference documents which are given by Shikha Ghildiyal above.

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Thank you for your support and understanding.

Best Wishes,

Alex Zhang