I've run Malwarebytes...nothing. Someone suggested Hijack this BUT I have no clue what I'm looking at.
It seems to only have happened once BUT I don't want my customers to block me so I'm trying to find a fix.
Your account has been hijacked - contact your ISP or email provider.
"hijack this" : Ususally only Pro malware fighters can interpret this. Whoever suggested it is an imbecile.