Problem: In certain cases Microsoft Ofice Outlook does not set itself as a default email client correctly. In this case the Print2Email detects the previous email client as a default, or cannot find any default email client. When trying to send the printed document with Print2Email using MAPI, Print2Email will use the client that was set as default before the installation of the Microsoft Office Outlook or returning with the following error message: default email client could not be found.

Solution: When this occurs, the user can set the default email client manually. The default email client can be set in the following locations:
Windows 8.1:
Control Panel > Default Programs > Set Default Programs > Select Thunderbird and click on the “Set this program as default” option.

Windows Vista/7 :
Start Menu > Default Programs > Set Your Default Programs
Windows XP:
Start Menu > Set Program Access and Defaults
or
Start Menu > Control Panel > Internet Options > Programs