I am using sSMTP with PHP for e-mail sending and it works fine.

The problem is that sSMTP performs the delivery synchronously which adds latency to my PHP scripts, letting the user waiting a little too long.

Is there a way to make it work non-blocking?

(I though of a hack on the shell, to start the sSMTP process on the background or something, and return earlier back to PHP, but I could not make it work.)