I 've had several problems virus invasions, server sending email, I have worked with cPanel servers, WHM, and others. I can fix your server for sure. Upgrade, repair, find hidden files.
What happens? You replace joomla, repairs, but are infiltrated small files that are used by the attacker to make a new invasion. I will take care of the virus and still stay 30 days monitoring your site to prevent a reinfestation. Hug.
I also request for reconsideration on google for you.