rotate ips exim

Here's a very easy way

create /etc/exim/exim.pl with the following content:


-----------------------------------

use feature qw[state];

sub randomhosts {
  state $current;

  my @inet = (
    "x.x.x.x:hostname1.domain.com",
    "x.x.x.x:hostname2.domain.com",
    "x.x.x.x:hostname3.domain.com"
  );

  if ($_[0] eq 'generate') {
    shift;
    @{$current}{qw[ip host]} = split /:/, $inet[rand @inet];
  }

  return $current->{$_[0]};
}


-----------------------


Replace the x.x.x.x with IP and the hostname ( after colon, which will be used as HELO).

Now add this to top of your exim.conf

perl_startup = do '/etc/exim/exim.pl'

Now, under remote_smtp: section append this

  interface = "${perl{randomhosts}{generate}{ip}}"
  helo_data = "${perl{randomhosts}{host}}"

That's it. Now emails will randomly go through all the IPs you added to Perl script, and will use the valid HELOs.