/usr/local/cpanel/Cpanel/DIp/MainIP.pm:
######################################################################
# getmainmailip
# Returns IP listed in /etc/mailips for sending email (using *:)
######################################################################
sub getmainmailip {
    my $etc_mailips = "$SYSTEM_CONF_DIR/mailips";
    my $etc_exim_localopts = "$SYSTEM_CONF_DIR/exim.conf.localopts";

    open(LOCALOPTS, $etc_exim_localopts);
    my @localopts = <LOCALOPTS>;
    close LOCALOPTS;

    open(MAILIPS, $etc_mailips);
    my $first_line = <MAILIPS>;
    close MAILIPS;

    my $search = "custom_mailips=1";
    my @custom_mailips = grep /$search/,@localopts;
    chomp @custom_mailips;

    my @mailips = split('\*: ', $first_line);
    my $mailip;
    if (@custom_mailips) {
      $mailip = $mailips[1];
      chomp $mailip;
    } else {
      $mailip = getmainserverip();
      chomp $mailip;
    }
    return $mailip;
}


###########################################################################################
/usr/local/cpanel/Cpanel/DIp.pm

 line 30:
 *getmainserverip  = *Cpanel::DIp::MainIP::getmainserverip;

 Add this at line 31:
 *getmainmailip    = *Cpanel::DIp::MainIP::getmainmailip;

###########################################################################################
/usr/local/cpanel/Cpanel/SPF.pm:
 
Line 57 original:
 my $mainip = Cpanel::NAT::get_public_ip( Cpanel::DIp::MainIP::getmainserverip() );

 Line 57 modified to use getmainmailip():

 my $mainip = Cpanel::NAT::get_public_ip( Cpanel::DIp::MainIP::getmainmailip() );

 Lines 100 and 191 original:
 my $mainip = Cpanel::NAT::get_public_ip( Cpanel::DIp::getmainserverip() );

 Lines 100 and 191 modified to use getmainmailip():
 my $mainip = Cpanel::NAT::get_public_ip( Cpanel::DIp::getmainmailip() );