Jeroen van Aart wrote:
> Thought you'd like to know.
>
> To quote
> http://projects.puremagic.com/greylisting/whitepaper.html?view=markup:
>
> "One issue is that some MTA software (Exim for example) attempts to
> limit the problem of forged sender addresses by attempting to verify
> that the claimed sender of an email is a valid address by doing an SMTP
> callback before accepting mail. Since it is desired to minimize the
> traffic when a mail may be rejected temporarily, the best course of
> action would be to issue a tempfail after the RCPT command. However, in
> the case of a SMTP callback, doing so at that point may cause our
> outgoing mail to be delayed unnecessarily."
>
> I don't think exim does that by default (anymore?). It could get you
> blacklisted someone wrote here recently.
>
> Regards,
> Jeroen
>
AFAIK, the 'generic' Exim hasn't done that 'by default' in donkey's
years - if it *ever* did.
What it did/does do is a mx *lookup* (against the nearest aware DNS) to
insure it at least 'seems to be able' to route a bounce (or ordinary
reply...), and even that only when configured to do so.
CAVEAT: I've never paid a lot of attention to the default config, so
could well be wrong.
Otherwise, yes - it looks as if the citation is in error, and shoudl
instead have said that Exim
'.. may sometimes be configured to do an smtp callout..'
Bill
