On Windows 7 and Windows 8.0 computers, the applications built on WinHTTP (Windows HTTP Services) such as Outlook, Word, etc. only support TLS 1.0. As a result of this, if you try to establish a secure connection from your Outlook client to a PTA IT Mail Server, Outlook will throw an error message “your server does not support the connection encryption type you have specified“.

In order to resolve this and allow your Outlook to communicate securely to the PTA IT Server using TLS 1.1 and TLS 1.2, you have to do the following:

  1. Install the Windows update KB3140245, either through Windows Update where it is available as an Optional Update, or download it from the Microsoft Update Catalog https://www.ptait.ie/downloads/TLS/KB3140245.msu
  2. Download the file MicrosoftEasyFix51044.msi from the following page and install it on your computer:
    https://www.ptait.ie/downloads/TLS/MicrosoftEasyFix51044.msi

https://support.microsoft.com/en-us/help/3140245/update-to-enable-tls-1-1-and-tls-1-2-as-a-default-secure-protocols-in

The file is available for download in the section labeled Easy fix on the above mentioned page. If the easy fix option is not suitable for you and you prefer to edit the registry of your computer manually, the article also provides that information in section “How the DefaultSecureProtocols registry entry works”.