This error may be triggered by different types of problems. It can occur when your default email client is set to a program that does not support Extended MAPI.
If this is the case, see if temporarily setting it as the default client fixes the issue and restart Aid4Mail. The instructions on how to change the default email client are below:
In Windows 10, search for "default programs" in the search bar next to the Start Button and select the "Default Programs" desktop application.
Then click on the application under "Email" and select Outlook.
In Windows 7, follow the steps on this video tutorial to set your default email client:
If the above doesn’t apply or the solution doesn't work, see if rebooting your computer fixes the issue.
If you experience any issues, please don't hesitate to contact us by raising a ticket.