What to do if international student exchange supervisor doesn't answer my email?
Professors are often very busy and receive many emails, sometimes more than a hundred a day. It is not uncommon that an email gets forgotten, especially if it was sent from a stranger. Since a week has passed, it is certainly appropriate to send another polite reminder. However, other strategies might be more effective:


Ask your local teacher about the issue or ask her to contact the Romanian teacher, explaining that you could not get a response although the issue is urgent.
Write an email to the Romanian supervisor's secretary/the secretary of the institute.
Call them on the phone


When writing email, make sure that the issue can already be understood from reading the subject line.