Our mail servers reject connections that don't follow the RFC. Am I wrong to do this? Seth, RFC 1122 (Requirements for Internet Hosts - Communication Layers) section 1.2.2 (Robustness Principle):
"Be liberal in what you accept, and conservative in what you send"
I would say this quotation of RC1122 1.2.2 seems a little bit out of context. "being liberal in what you accept" in terms of such egregious errors as a mailformed destination address does not mean you necessarily pass the message on. The robustness principal doesn't say you have to correct the error and accept the message, continuing normally, as if there was no error, it says you're prepared for it To be robust, your SMTP server implementation must not crash if a user omits the angle brackets, it must be prepared to accept the malformed text, and respond accordingly, I.E. Refuse the message, with an error response, if it doesn't recognize the proper destination format. The following paragraph of RFC1122 states: "Software should be written to deal with every conceivable error, no matter how unlikely; sooner or later a packet will come in with that particular combination of errors and attributes, and unless the software is prepared, chaos can ensue. In general, it is best to assume that the network is filled with malevolent entities that will send in packets designed to have the worst possible effect. This assumption will lead to suitable protective design, although the most serious problems in the Internet have been caused by unenvisaged mechanisms triggered by low-probability events; mere human malice would never have taken so devious a course! " -- -J