Do I need to associat another vlan to the existing port?

I have a Cisco asa 5505 security appliance running on my network.
I have 3 Servers for convience ...
serv1 DC, DHCP, DNS
serv2 Exchange
serv3 IIS
I have 3 vlans ...
interface Vlan1
 nameif inside
 security-level 100
 ip address 192.168.2.1 255.255.255.0
!
interface Vlan2
 nameif outside
 security-level 0
 ip address xx.xx.xx.188 255.255.255.192  <---- There are 2 active IP addresses in this subnet
!
interface Vlan3
 nameif dmz
 security-level 50
 ip address 192.168.1.1 255.255.255.0


My Issue.
I have clients getting rejections from sbcglobal on dns failures.
mail.domain.com rDNS xx.xx.xx.188
Now the difficulties. Mail is  set up to go through xx.xx.xx.189
access-list inbound extended permit tcp any host xx.xx.xx.188 eq www     <--- Serv3
access-list inbound extended permit tcp any host xx.xx.xx.188 eq ftp         <--- Serv3
access-list inbound extended permit tcp any host xx.xx.xx.188 eq https     <--- Serv3
access-list inbound extended permit tcp any host xx.xx.xx.189 eq smtp     <--- Serv2
access-list inbound extended permit tcp any host xx.xx.xx.189 eq pop3     <--- Serv2
access-list inbound extended permit tcp any host xx.xx.xx.189 eq imap4    <--- Serv2
access-list inbound extended permit tcp any host xx.xx.xx.189 eq https     <--- Serv2 (owa)

static (dmz,outside) tcp interface www 192.168.1.3 www netmask 255.255.255.255
static (dmz,outside) tcp interface ftp 192.168.1.3 ftp netmask 255.255.255.255
static (dmz,outside) tcp interface https 192.168.1.3 https netmask 255.255.255.2
55
static (inside,outside) tcp xx.xx.xx.189 https 192.168.2.38 https netmask 255.2
55.255.255
static (inside,outside) tcp xx.xx.xx.189 pop3 192.168.2.38 pop3 netmask 255.255
.255.255
static (inside,outside) tcp xx.xx.xx.189 smtp 192.168.2.38 smtp netmask 255.255
.255.255
static (inside,outside) tcp xx.xx.xx.189 imap4 192.168.2.38 imap4 netmask 255.2
55.255.255


Ok.
ALL traffic flows through, With the exception of Serv2. Even though mail flows in and out I have rDNS failures from sbcglobal.net my IP resolves to xx.xx.xx.188 when everything is set for 189.
I have verified outside DNS mx points to A, and A points to 189. However still resolving to 188
Should be resolving to .189