A method of resolving by an original network/domain of a telephone number of a called party, belonging to a recipient network/domain. The method includes: a) a calling party, belonging to the original domain dispatches a message using the telephone number of the called party as routing identifier; b) a server of the original domain in charge of routing the message, or a DNS server, produces an interrogation key dependent on the telephone number and on a penultimate domain name; c) a DNS request is sent to a DNS server associated with the penultimate domain; d) the DNS server associated with the penultimate domain performs, by using the interrogation key, a search in a database ENUM associated therewith; e) the search provides at least one record containing a return network/domain including the recipient domain; and f) a DNS request is sent to the return domain.