1. A method comprising: receiving a first type of electronic message; determining that the first type of electronic message is addressed to a telephone number; identifying, within the received first type of electronic message, a first type of source indicator that indicates a source of the first type of electronic message as an intended destination of a reply message; identifying a first user account associated with the telephone number; preparing, using at least one processor, a second type of electronic message based on the content of the first type of electronic message and comprising a second type of source indicator based on the indication of the first type of source indicator; sending the second type of electronic message to the identified first user account; and based on determining that the first type electronic message is addressed to the telephone number, and further based on sending the second type of electronic message to the identified first user account associated with the telephone number, generating a reply source indicator for any reply message received from the first user account, wherein the reply source indicator comprises the telephone number.