A method for sending a secure e-mail message to an identified recipient using a communication device, the communication device comprising a messaging application and a key store for the storage of security certificates associated with recipients, the method comprising the steps of: upon selection of a send option of the messaging application to initiate a message sending sequence of the messaging application to send a composed and addressed e-mail message, the messaging application determining that the composed and addressed e-mail message is to be sent securely to the identified recipient such that the step of the messaging application determining that the composed and addressed e-mail message is to be sent securely to the identified recipient comprises the step of accessing information on the communication device representing a security policy for e-mail messages composed on the communication device, and prior to sending said e-mail message, the messaging application accessing the key store to determine if a security certificate associated with the identified recipient is present at the communication device; on condition that the security certificate associated with the identified recipient is present, retrieving the security certificate associated with the identified recipient from the key store, or on condition that no security certificate associated with the identified recipient is present in the key store, accessing, over a network, one or more certificate services to retrieve a security certificate associated with the identified recipient; determining whether validation of the security certificate thus retrieved is required and, on condition that validation is required, the messaging application querying an external certificate status provider to determine the validity of said security certificate; on condition that the retrieved security certificate is invalid, the messaging application accessing the one or more certificate services to obtain a valid retrieved certificate; on condition that a valid security certificate has been retrieved, the messaging application encoding the e-mail message using information contained in said valid security certificate; and the messaging application sending the encoded message to the identified recipient. the messaging application accessing the key store to determine if a security certificate associated with the identified recipient is present at the communication device; on condition that the security certificate associated with the identified recipient is present, retrieving the security certificate associated with the identified recipient from the key store, or on condition that no security certificate associated with the identified recipient is present in the key store, accessing, over a network, one or more certificate services to retrieve a security certificate associated with the identified recipient; on condition that the security certificate associated with the identified recipient is present, retrieving the security certificate associated with the identified recipient from the key store, or on condition that no security certificate associated with the identified recipient is present in the key store, accessing, over a network, one or more certificate services to retrieve a security certificate associated with the identified recipient; determining whether validation of the security certificate thus retrieved is required and, on condition that validation is required, the messaging application querying an external certificate status provider to determine the validity of said security certificate; on condition that the retrieved security certificate is invalid, the messaging application accessing the one or more certificate services to obtain a valid retrieved certificate; on condition that a valid security certificate has been retrieved, the messaging application encoding the e-mail message using information contained in said valid security certificate; and