SMTP Security Issues

When it comes to security and SMTP, the theme is a common one in TCP/IP: A lack of security in how the protocol is implemented, because it was developed when the Internet was just a small group of machines controlled by individuals who mostly knew and trusted each other or who were able to use physical security. Developers never imagined TCP/IP being used by millions of anonymous average Joes around the world, which necessitates far more attention to security than a small research internetwork like the ARPAnet.

With SMTP, security matters are, if anything, worse than they are with some of the other protocols. Not only does SMTP not have any real security mechanism, the original relaying model of SMTP communication is entirely ...

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