Re: ouch

> Since every other mail that I know of generates upper case HELO, and
> only exim (as far as I know) generates mixed case, I suggest that it
> is both expedient and more robust for exim to generate upper case HELO.
> The basic principal (which is being violated here) is that a robust
> program should be liberal in what it accepts and conservative in what
> it generates. In other words, obstinate purity is NOT robust.

The "be conservative in what you send" principle is not being broken here.
Exim is sending a "helo" command that precisely conforms to both the
letter and the spirit of the Standard.

The other mailer is clearly broken. While changing exim to work around
this problem might be useful in the short term, I do not believe that it
is useful in the long term (where it is better to ensure that broken
mailers get fixed).

I encourage the maintainers of working code to refrain from adding kludges
to accommodate broken code. I believe that this strategy will, in the
long term, cause the broken code to get fixed or to die out, and that
either of those results will be better than the status quo.

--apb (Alan Barrett)