system_setfrom
php
void system_setfrom(string $adres_email , [string $nadawca])Sets the From field of the outgoing message. If only $adres_email is supplied, only the email address is set. The optional second argument $nadawca specifies the sender name.
NOTE: Works only while a mailing is being sent.
Example:
php
system_setfrom('sarescript@sare.pl', 'SAREscript');