Islam doesn’t generally forbid dealings and contacts between members of the opposite sex. What Islam assures that such dealings should be pure, decent, and of good goal.
A Muslim woman, when dealing with men, should be modest and dressed properly. She should wear the hijab, and stick to the general ethics and morals of Islam. A Muslim man, when dealing with women, should be modest and sticking to Islamic morals of dress, talking, etc. Both Muslim women and men should lower their gazes and avoid looking lustfully on members of the opposite sex.
In brief, we could say that Islam allows decent, pure, and moral dealings between men and women; while it forbids immorality and immodesty in any aspect or form.