Description

On 23 July 2018, SparkPost deprecated TLSv1.0. This caused Email Delivery Service unavailability for Sitecore XP solutions running on .NET Framework 4.5.2. The attempts by Sitecore XP to make a call to the Email Delivery Service are unsuccessful and an exception is thrown.

This applies to EXM 3.4 — 3.5 versions.

Identification

Prerequisites:

• Sitecore XP versions 8.2 Initial Release – 8.2 Update-7.
• Solution running on .NET Framework 4.5.2.
• Email Delivery Service installed.

Examples of actions that require connection to SparkPost:

• Suppression List management.
• Send Email.
• Bounce Check.
• Spam Check.

Examples of errors:

The underlying connection was closed: An unexpected error occurred on a send.

Unable to read data from the transport connection:
An existing connection was forcibly closed by the remote host.

Failed to read beginning of SSL/TLS record.

Solution

To resolve the issue, consider one of the following options:

• Upgrade Sitecore XP instance to Sitecore XP 9.0.0 or later.
• Download and install the patch compatible with the affected product version found on this page (see installation instructions inside the archive): https://github.com/sitecoresupport/Sitecore.Support.173301/releases
• Proceed as follows:
  
  1. Install .NET Framework 4.6 or 4.6.1.
  2. Modify the targetFramework attribute of the httpRuntime node in the Web.config file, as follows:

     <httpRuntime targetFramework="4.6" ... />