a!safeLink close window automatically

Ramesh -
I don't have any suggestions to close the window.
But, a couple of things -
(1) Your approach is clever, but it pushes the limits of how safelinks are intended to be used. Specifically, you are leveraging implicit features of the browser and the operating system to open the draft email. This is not supported functionality of the product. It cannot be guaranteed to work in the future.
(2) When a users clicks this link, they are effectively exiting your Appian process. This limits your ability to manage your process fully and track how the process is being used. Consider instead collecting the message details in an Appian user task form and sending email using the send email smart service. For even more detailed control, assign a task instead of sending an email.

Ramesh -
I don't have any suggestions to close the window.
But, a couple of things -
(1) Your approach is clever, but it pushes the limits of how safelinks are intended to be used. Specifically, you are leveraging implicit features of the browser and the operating system to open the draft email. This is not supported functionality of the product. It cannot be guaranteed to work in the future.
(2) When a users clicks this link, they are effectively exiting your Appian process. This limits your ability to manage your process fully and track how the process is being used. Consider instead collecting the message details in an Appian user task form and sending email using the send email smart service. For even more detailed control, assign a task instead of sending an email.