Resumen
This article focuses on the need for more secure emails. Secure messaging means the ability to provide data confidentiality and non-repudiation of origin services for email. It informs that the technologies to provide these services are cryptography in general, and data encryption, digital envelope and digital signature mechanisms in particular. It is felt that Web-based messaging has made the problem of how to securely store and use private keys more challenging. Consequently, the deployment of secure messaging has turned out to be slower than expected. It is agreed that no implementation will be free of bugs, and sooner or later some of these bugs will be found and exploited. Certified mail schemes based on trusted systems, which look fine in theory, have been questioned because their usefulness and security are often overestimated. The technologies and solutions that can be used to provide certified mail services on the Internet have been discussed in detail and among these approaches, the use of online trusted third party (TTPs) is found most appropriate.