It is difficult to tell for what purposes the e-mail address of other user of VKontakte can be necessary. But if so this information, that is a number of ways by means of which it is possible to make it is necessary for you.
1. Find the user's mail by means of mail agent. Such focus can pass only if the person interesting you has e-mail registered on www.mail.ru. Certainly, you should be registered too there.
Find a name and a surname of the user of VKontakte and enter this information into search of people in the mail agent. And everything, further you find e-mail of the necessary person in the received questionnaire.
2. Learn personally from the user its e-mail. Legal ways to learn the e-mail address except search through mail agent do not exist. It is possible to use, of course, different programs which will crack the page of the user, but it will already be outright violation of safety of the website www.vkontakte.ru. It can threaten you with blocking of your account, at worst will cause this action administrative responsibility.
You can ask directly the person its e-mail address, and you can find this information indirectly, having asked it to send any document to your e-mail. The truth is not present a guarantee in this case that the file requested by you will come from the address of mail used by VKontakte.
3. Pick up the e-mail address analytically. If you cannot openly ask the e-mail address for the user of VKontakte in any way, but there is a wish to make it very much, then it is possible to try to pick up this address.
Most often use for writing the e-mail addresses a name and a surname. Between them often there are some punctuation marks: points, hyphens. A set of certain digits, for example, year of birth of the user is also periodically used. Further substitute to the made combination the termination of popular mail services, for example, of mail.ru, gmail.com, hotmail.com
Send any trial letter to presumable mail. However It is necessary to tell at once that path is extensive. Guess mail address extremely hard. There is no high probability that your letter will not be ignored.