If you missed the Trial Time and would like to extend it, then select the menu item "Request Trial Extension" from the Application menu. You will see the following dialog:
The user name of the computer is entered automatically and can't be changed. The Email Address is the address the Trial License is sent to. After clicking on the button "Extend Trial" the available information is sent to Moth Software. The email is sent via SendGrid.
Mail Archiver X support will send you a license file, which you should save somewhere. Select the menu item "Reset Trial Time". This will show a file open dialog. Select the license file and that's it. This can only be done once with a license file.