Copy /bin/service/!tcp25 to /bin/service/tcp25.	You may	need
to make	some changes.

Make sure to chmod +x /bin/service/tcp25 or  else  the	mail
server won't be	able to	start


  ; cat	/bin/service/tcp25
  #!/bin/rc
  #smtp	serv net incalldir user

  user=`{cat /dev/user}
  exec upas/smtpd -e -f	-r -s -n $3


If you have a certificate you have  generated  using  acmed,
you can	enable StartTLS	with -c:


  exec upas/smtpd -c /sys/lib/tls/acmed/example.com.crt	-e -f -r -s -n $3



Note: the -c argument currently	has a bug where	it does	 not
send the full chain of the TLS certificate, so email clients
that connect to	 it  may  report  a  certificate  validation
error.


Make sure to edit /mail/lib/smtpd.conf:


























		     November 23, 2024






			   - 2 -


  #
  #	  sample smtpd configuration options for inside	connections
  #

  #
  #	  replace example.com with the name of your domain
  #	  replace 198.51.100.0 with the	IP address range of your networks

  defaultdomain		  example.com
  norelay		  on
  verifysenderdom	  off	  #disable dns verification of sender domain
  saveblockedmsg	  off	  #save	blocked	messages

  #
  # if norelay is on, you need to set the
  # networks allowed to	relay through
  # as well as the domains to accept mail for
  #

  ournets 198.51.100.0/24

  ourdomains *.example.com

  Copy /mail/lib/rewrite.direct	to /mail/lib/rewrite, while replacing YOURDOMAIN.DOM with your actual domain name.

  You will also	want to	edit /mail/lib/names.local for the users you want to handle mail for.

  Edit /mail/lib/remotemail to add the -C -s flags to turn on TLS encryption when sending.
  -C is	needed in case some certificates don't validate	properly:

  #!/bin/rc
  shift
  sender=$1
  shift
  addr=$1
  shift
  fd=`{/bin/upas/aliasmail -f $sender}
  switch($fd){
  case *.*
	  ;
  case *
	  fd=example.com
  }
  exec /bin/upas/smtp -C -s -h $fd $addr $sender $*

  Make sure to replace example.com with	your actual domain name.

  If you are logged in as a user other than the	default	hostowner (glenda),
  make sure to add the users to	upas group:

  ; echo 'newuser upas +$username' >> /srv/cwfs.cmd

  Then create the user's mailbox:



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			   - 3 -


  ; upas/nedmail -c



See dkim.ms guide for enabling dkim. Make sure	to  add	 spf
and  dmarc  records  as	 indicated in ndb.ms guide.  To	test
sending	an email:


  ; upasname=sender@example.com	upas/marshal -s	'Alpha Bravo Charlie' recipient@example.org


Type a message,	then a newline,	then EOF.

If your	email address is simply	$user, you may	be  able  to
omit  the upasname variable provided the domain	is correctly
configured elsewhere.

To offer SMTP over TLS (submission port), we can  no  longer
use /bin/service files,	since by default, it starts the	pro-
cess as	user none.

Instead, we will start upas/smtpd from	cpustart,  and	call
aux/listen with	-t.

cpu%	mkdir	  /cfg/$sysname/service.upas	 cpu%	  cp
/bin/service/!tcp25 /cfg/$sysname/service.upas/tcp587

Then, we edit tcp587:

cpu% cat /cfg/$sysname/service.upas/tcp587 #!/bin/rc

user=`{cat /dev/user}

exec upas/smtpd	-a -d -c  /sys/lib/tls/acmed/example.com.crt
-e -s -n $3

A line such as below must be added to /cfg/$sysname/cpustart
to call	service.upas:

auth/as	upas aux/listen	-p 128 -t /cfg/$sysname/service.upas

Warning: Calling auth/as may corrupt the namespace, and	 may
require	you later to call mntgen /mnt.

Make sure to set the file as executable:

cpu% chmod +x /cfg/$sysname/service.upas/tcp587








		     November 23, 2024