Hi Mirjana!
Recently, we responded to requests from the ePals teaching community to make improvements to the functioning of ePals' messaging tool to enable ePals teachers to use their ePals account to email with the whole world. So, that is why you are receiving spam - a teacher or parent account is no longer limited to within ePals.
Your students, though, are still working within a safe, protected environment. They can only email with other ePals students and will not receive spam.
Sheila