Dr. Muzammil H. Siddiqi, former President of the Islamic Society of North America, states: According to Muslim jurists, it is not permissible to marry someone by mail or phone. The same thing can be said about the e-mail. Marriage in Islam is a formal legal contract. It should be very clear who is marrying whom. The Shari`ah emphasizes the announcement of marriage and does not allow any ambiguity in this matter. It is for this reason witnesses for Nikah are necessary.
If the parties who want to get married are not present, they can appoint a wakil (representative). The person who is getting married has to appoint his/her wakil. It is permissible to appoint a wakil through telephone, fax or email. The wakil then should do the ijab (proposal) or qubul (acceptance), in person, on behalf of the person who appointed him. Two witnesses who also personally know the party that is not present are necessary for the contract of marriage.