Microsoft announced in January 2020 that they would begin deprecating support for TLS versions 1.0 and 1.1 for Microsoft 365. As of October 15, 2020 deprecation will begin for all commercial customers, including those using POP3, IMAP4 and SMTP to exchange email.
This change by Microsoft will affect older versions of SocketTools which do not support TLS 1.2, as well as any applications using SocketTools running on Windows XP or Windows Vista.
Your application will be affected by these changes if you are using SocketTools mail components connecting to outlook.office365.com or any of the related domains.
For a comprehensive list of which platforms support TLS 1.2, refer to our knowledge base article which lists supported TLS versions on Windows.
If you are using an older version of SocketTools, we recommend you upgrade to the current version as soon as possible. In addition to support for TLS 1.2, the current version also supports OAuth 2.0, which is required for newly created tenants using Exchange, including POP3 and IMAP4 services.
Although Microsoft has deferred the end of support for basic (password) authentication until the later half of 2021 for legacy tenants, you should take this time to ensure your application has support for both TLS 1.2 and OAuth 2.0 if you're connecting to Microsoft 365 Exchange servers.
If you have an older SocketTools development license, you can upgrade to the current version at a reduced cost. Please contact technical support if you have any questions or concerns about upgrading your projects.