Basically, the value in the "Full Name" field is different than what you have prefixed in your email field. In the mIRC options window (alt+o), in the connection area, you'll notice 4 immediate fields. Full Name, Email, Nick, and Alt. Nick. The fullname must be the same value as what prefixed the @ in your email address. Ex:

Full Name: KingTomato
Email: KingTomato@kingtomato.com

That would work.

Full Name: King T. Mato
Email: KingTomato@kingtomato.com

that however, will not. Simply match the values of the italics in both fields, and you should be fine.