Microsoft modern authentication deadline looms over Exchange

<section class="section main-article-chapter" data-menu-title="Office 365 services that will be affected Without a migration to modern authentication Basic authentication in Exchange Online. Microsoft will stop support for basic authentication in Microsoft Exchange Online services on Oct. 1. Components related to the hosted email platform that will not function include Exchange Online for Exchange ActiveSync, Exchange Web Services, IMAP, Offline Address Book, POP and remote PowerShell.

Outlook client support for Exchange Online. After the deadline, some older versions of Microsoft Outlook will not receive email, including Outlook 2010 and Outlook 2013 for Windows and Outlook for Mac 2011. Organizations that use these legacy versions will need to upgrade to avoid any disruption.

Compliance and cybersecurity pressures. The increase in email phishing attempts and hijacked user accounts have many companies, including several cybersecurity firms, mandating the use of MFA for email. In Office 365, modern authentication is required for MFA.