seperate ip address for outgoing email only

[Rajesh M]

ello

we are a corporate email service provider only transactional / business emails.

Once in a while under rare occasions due to customer's email id getting compromised our server's primary ip gets blacklisted in spam databases.

So the question is

Can we change the outgoing mails' ip address in POSTFIX during such rare occasions only for OUTGOING emails, while having the MX ip without any change.

all our services smtp, pop and imap are in the same server.

thanks
rajesh

[Wietse Venema]

Rajesh M:

> ello
>
> we are a corporate email service provider only transactional / business emails.
>
> Once in a while under rare occasions due to customer's email id getting compromised our server's primary ip gets blacklisted in spam databases.
>
> So the question is
>
> Can we change the outgoing mails' ip address in POSTFIX during such rare occasions only for OUTGOING emails, while having the MX ip without any change.
>
> all our services smtp, pop and imap are in the same server.

Set up a dedicated SMTP client in master.cf with a unique
smtp_bind_address and smtp_helo_name that matches that IP address.

    smtp-1.2.3.4       unix  -       -       n       -       -       smtp
        -o smtp_bind_address=1.2.3.4
        -o smtp_helo_name=helo-for-1.2.3.4

Then configure sender_dependent_default_transport_maps, returning
that dedicated SMTP client.

Example entry:

    [hidden email] smtp-1.2.3.4:

(or "@example.com  smtp-1.2.3.4:" for all senders in a domain).

        Wietse