When i send an email, i have a PTR record for my hostname server.domain.com it has IP 192.168.0.1 (not real IP, but i dont want to publish my server IP)
I also have an addon IP address 192.168.0.2
IPs and hostname is changed to make this simple.

When i send an email it uses the 192.168.0.2 IP address and not the one for the hostname, this has the "wrong" PTR record, and so gmail blocks the email because its not "correct" ptr and several other parameters.

How do i change this so it doesnt happen? server sends around 1000-2000 mail a day and about 50-100 are blocked. this is quite irritating that it does not use hostname and server IP in CWP for sending email. it uses ANY ip address!

 

Quote

    gmail-smtp-in.l.google.com[108.177.15.27] said: 550-5.7.1 [xx.xx.xx.xx
    18] Our system has detected that this message is 550-5.7.1 likely
    suspicious due to the very low reputation of the sending IP 550-5.7.1
    address. To best protect our users from spam, the message has been
    550-5.7.1 blocked. Please visit 550 5.7.1
    https://support.google.com/mail/answer/188131 for more information.
    z5-20020a05600c0a0500b003fbef8ad8f5si3205315wmp.40 - gsmtp (in reply to end
    of DATA command)

 

did you try it?

 

That is per user account mi have that oronlemnserverwide. How do i fix that? 

you need to configure the postfix like the below :

in /etc/postfix/master.cf

smtp      unix  -       -       n       -       -       smtp
  -o smtp_bind_address=100.100.100.100
# When relaying mail as backup MX, disable fallback_relay to avoid MX loops
relay     unix  -       -       n       -       -       smtp
        -o smtp_bind_address=100.100.100.100
        -o fallback_relay=
#       -o smtp_helo_timeout=5 -o smtp_connect_timeout=5

 

Quote

smtp      unix  -       -       n       -       -       smtp
# When relaying mail as backup MX, disable fallback_relay to avoid MX loops
relay     unix  -       -       n       -       -       smtp
        -o fallback_relay=
#       -o smtp_helo_timeout=5 -o smtp_connect_timeout=5

That is what i have in my master file now.

edit that to this:

Quote

smtp      unix  -       -       n       -       -       smtp
  -o smtp_bind_address=100.100.100.100
# When relaying mail as backup MX, disable fallback_relay to avoid MX loops
relay     unix  -       -       n       -       -       smtp
        -o smtp_bind_address=100.100.100.100
        -o fallback_relay=
#       -o smtp_helo_timeout=5 -o smtp_connect_timeout=5

So just adding the line to smtp AND relay lines then

 

Quote

-o smtp_bind_address=100.100.100.100

 

I will try this after a reply