AUTH PLAIN response is malformed

[kylegoetz]

AUTH PLAIN
334

However, the RFC that defines SMTP replies states

Formally, a reply is defined to be the sequence: a
three-digit code, , one line of text, and , or a multiline
reply (as defined in the same section). Since, in violation of this
specification, the text is sometimes not sent, clients that do not
receive it SHOULD be prepared to process the code alone (with or
without a trailing space character).

In the specification for AUTH PLAIN, teh RFC itself does deviate from this spec in an example, even the example explicitly states in their deviating example that there is still a space after the reply code:

C: AUTH PLAIN
(note: there is a single space following the 334
on the following line)
S: 334