mail not working in windows 10 Microsoft released Windows 10 free upgrade to Windows 7, 8, and 8.1 users on July 28th, 2015. This remake of Windows currently has numerous known issues with pre-existing email client configurations. Users may experience error messages when attempting to Send or Receive email using their regular email client.
The most common problem is that Windows 10 has disabled the deprecated Secure Sockets Layer (SSL) security on all connections by default, and only allows Transport Layer Security (TLS) connections. If you configured your email accounts in your email client to use SSL these settings would need to be changed as follows: