Exchange of letters and E-mail

E-mail and exchange of letters are semantically related. In some cases you can use "E-mail" instead a noun phrase "Exchange of letters".

E-mail noun - (computer science) a system of world-wide electronic communication in which a computer user can compose a message at one terminal that can be regenerated at the recipient's terminal when the recipient logs in.

Exchange of letters and e-mail are semantically related. You can use "Exchange of letters" instead a noun phrase "E-mail".