= s/qmail/DOC/smtpd =

https://www.fehcom.de/sqmail/man/qmail-smtpd.html
  機能強化されたsmtpd

RBL検査を挟むなら: https://notes.sagredo.eu/en/qmail-notes-185/setting-up-rblsmtpd-127.html
  http://www.fehcom.de/ipnet/ucspi-tcp6/rblsmtpd.html
----

qmail-smtpd includes a 'MailFrom:' parameter parser and obeys 'Auth', 'Size',
  and 'SMTPUTF8' advertisements.  
qmail-smtpd supports SMTPUTF8 SMTP envelope addresses
       and provides 8 bit clean message transmission.  qmail-smtpd STARTTLS
       and SMTPS implementation requires the use of sslserver from ucspi-ssl.


== TRANSPARENCY ==
badmailfrom   Unacceptable envelope sender addresses.  
  qmail-smtpd will reject every recipient address for a message 
  if the envelope sender address is listed in badmailfrom. 
  * A line in badmailfrom may be of the form @host, meaning every address at host.
   Additionally, any envelope sender address can be filtered with a wildmat check:
{{{
              *@earthlink.net
              !fred@earthlink.net
              [0-9][0-9][0-9][0-9][0-9]@[0-9][0-9][0-9].com
              answerme@save*
              *%*
              @yahoo.com-
              @hotmail.com=
              @mydomain.tld+
              ~yahoo.com
              ?nobody@example.com
}}}
A badmailfrom file with this contents reject all mail from Earthlink except from fred@earthlink.net. 

It also rejects all mail with addresses like: 12345@123.com and answerme@savetrees.com.
            
Further, any mail with a sender address containing a percent sign (%) is rejected.

This implementation recognises 'extended' addresss in badmailfrom
allowing to reject mails with particluar spoofed domain addresses:

 . (1) The address is appended with a '-'.  Now, if TCP(6)REMOTEHOST
            equals 'unknown', mails with the corresponding address are
            rejected (badmailfromunknown).

 . (2) The address is appended with a '='.  In case TCP(6)REMEOTEHOST
            is set mails, whose domain part of the envelope addresses not
            matching the corresponding entry are rejected
            (badmailfromwellknown).

 . (3) The address is appended with a '+'.  If RELAYCLIENT is not set
            and the sender address matches a corresponding entry (anti-
            spoofing for internal addresses).

 . (4) The address is enhanced with a leading '~'.  This requires a
            (left to right partial) matching of TCP(6)REMOTEHOST with the
{{{
              *
              !
              !*@*.*
              *viagra*
}}}
== ENVIRONMENT VARIABLES READ ==
HELOCHECK=""
   enables a check of the provided HELO/EHLO greeting against the content of the control file badhelo. 
 
 * In case no HELO/EHLO greeting is given, SMTP connections can be rejected,
   if HELOCHECK='!' is set.

 * Checks on the presence and the content of the HELO/EHLO greeting string is facilitated,
   setting HELOCHECK='.'.  

 * To enforce the match of the HELO/EHLO greeting with the remote host's FQDN ( TCP(6)REMOTEHOST),
   use HELOCHECK='='.

HELOCHECK='A' | HELOCHECK='M'
   enable DNS A/MX lookup for the HELO/EHLO greeting string. 
   In addition, the HELO/EHLO string is checked against the content of badhelo.

Controlling the SMTP Mail From:

Controlling the SMTP RCPT TO:

Controlling the email body:

Environment variables for SMTP authentication:

Setting up the TLS/STARTTLS environment:

Other environment variables used: