NethServer 6

The commands below set up a custom-template based implementation:

    # config setprop postfix HeloHost mail.cliente.it
    # mkdir -p /etc/e-smith/templates-custom/etc/postfix/main.cf
    # cat - > /etc/e-smith/templates-custom/etc/postfix/main.cf/90custom_helo <<EOF
#
# 90custom_helo (custom template)
# rif 2014061110000101 #2767
#
{ \$postfix{'HeloHost'} ? "" : "# " }smtp_helo_name = { \$postfix{'HeloHost'} }

EOF
     # signal-event nethserver-mail-common-save

Test case

Here we check the EHLO SMTP command sent by Postfix smtp client process when it talks to other mail servers.

• Create a transport to the test smtp server:

  mkdir -p /etc/e-smith/templates-custom/etc/postfix/transport
  echo "qa2727.tld smtp:[127.0.0.1]:11025" > /etc/e-smith/templates-custom/etc/postfix/transport/20QA2727
  signal-event nethserver-mail-common-save
  

• Start smtp-sink SMTP server:

  smtp-sink -q EHLO,HELO -v -u postfix 127.0.0.1:11025 3 &
  

• Send a message:

  echo "helloworld" | mail -s test someaddress@qa2727.tld
  

  You should see smtp-sink: output on your console:

  smtp-sink: connect (AF_INET 127.0.0.1)
  smtp-sink: vstream_tweak_tcp: TCP_MAXSEG 16384
  smtp-sink: fd=5: stream buffer size old=0 new=32768
  smtp-sink: smtp_stream_setup: maxtime=100 enable_deadline=0
  smtp-sink: EHLO davidep2.vboxnet0.tld
  smtp-sink: disconnect
  

  The message is still on your queue (see mailq output). To send it again flush the queue typing:

  postqueue -f
  

• Change HeloHost prop value, signal-event nethserver-mail-common-save
• Check EHLO line changes accordingly when message is sent, repeating the step above