Sendmail applet may need to validate on RCPT

[Vladimir Dronnikov]

>> Is this the problem of BB sendmail, or none sendmails can do that?

>
> At the moment (busybox 1.13.3 for me) the sendmail applet tries to AUTH
> only if a MAIL FROM fails.
> In my mail server i've got rules that specify that you need to be
> authenticated to relay messages (send messages to other domains from
> non-local IP addresses).

Sorry, I just didn't get you. What _your mail server_? You use BB
sendmail as an MTA to talk to ISP mail server and the former refuses
to run the scenario you need, right? So I ask whether full-blown
sendmail can run that scenario talking to ISP mail server. In other
words, are you requesting for a feature that does exist in vanilla
sendmail?

> May internet service providers require users to authenticate before sending mail.

They do good. Spam is evil.

>> We should first consult SMTP RFCs for validity of such a scenario.
> http://tools.ietf.org/html/rfc2554 is the RFC we should look into.
> http://qmail.jms1.net/test-auth.shtml -> qmail hints that AUTH should go before MAIL FROM.

Aha.

> The deal is that sendmail.org knows if you need to auth only when it
> knows who the mail is addressed to. Depending on configuration options
> if the "to" is a server-handled domain then it won't need auth. But if
> the mail is going somewhere else it needs your user/password to allow this.
> The RFC basically says that you AUTH before EHLO or during FROM.
> At the moment busybox tries to AUTH only if necessary by checking the
> SMTP answer.
> An option would be required to "force" AUTH before FROM (or just enable
> it for that matter) otherwise it could sleep on cred not being available
> or being unnecessary on a tty.

I see. So what option commands vanilla sendmail to behave that way?
You saw the code -- it is hard to find a free letter :))

Regards,
--
Vladimir