Exchange Online to Deprecate Legacy TLS for POP3 and IMAP4
Microsoft will start to refuse inbound IMAP4 and POP3 client connections using legacy TLS versions (1.0 and 1.1) in July 2026. The move is consistent with other projects to remove obsolete or insecure email protocols from Exchange Online to increase the overall security of the online email service. In this article, we examine some methods to understand the POP3 and IMAP4 usage within a tenant.