Mail Engin automatically changing

[GrahamW]

When using the built in form tools on a layout Grid and using the built in form processor I leave the mail engin on default then after I save the work and close all the open boxes and go back to the grid and then if I re open it again the mail engine has changed from Default to PHOMailer - SMTP and the form fails.
How can I get it to stay on Default which works.

Graham

[Pablo]

You most likely enabled another option which requires PHPMailer.
For example, if you select Rich text format.

If you need further assistance then please share a DEMO project, so I can see what you have done.