Outgoing Mail disbaled

Hello Zoho,

A user under my domain [hello(at)thengmag(dot)com] outgoing mail is disabled. Incoming mails still come through, however, I can't send outgoing mails. I noticed in the admin section that the Outgoing mails have been disabled, however when I try and enable it, I get the error message: Operation permitted for paid user(s) only. would absolutely love if this could be fixed.

thank you.
kind Regards