When sending e-mail, time differences are of little importance, BUT the vast majority of women in the ex-USSR are using e-mail addresses that belong to their office or school.
Often, they have limited access to the system. At some universities, for example, students are only allowed to use a departmental PC one or two times a week for e-mailing, and the messages must be kept down to below one page.
Similar restrictions are usually enforced in government offices. What this means is that even though e-mail usually reaches its destination fairly quickly,
you may not hear back from your lady for 3 or 4 days, maybe even a week or more.
Bear in mind that she must also translate your e-mail message into English as well as their reply to it, and this takes time, too.
If the delay seems unusually long, you can send the message again, but be careful not to become a nuisance to whoever is running the system. Administrators in that part of the world can be very difficult to deal with.