Two separate WHM servers for web and email

Hi guys, (posted this over in the email section but that was probably the wrong spot? It's likely more to do with DNS zones) I am in the process of migrating all of my hosting to Amazon AWS after a series of outages with my current host. I want to run two WHM servers, one for websites, one for mailboxes/email. The websites one will also handle DNS Zones. I have created TWO Amazon EC2 instances with WHM running: 1. websites.domain.com acts as the website server (connected to an RDS database server), along with also being the DNS Zone manager. It has two elastic/static IP addresses for ns1 and ns2.domain.com 2. email.domain.com acts as the email server. It has an elastic/static IP also. I create cPanel accounts for each domain on BOTH machines. I edit the DNS Zone on websites.domain.com to point all MX to email.domain.com and email.domain.com A record points to the IP of email.domain.com I am successfully receiving emails at email.domain.com. I AM NOT able to send/deliver emails from email.domain.com Email deliverability report on email.domain.com says connection timed out. Mail queue says the messages are 'queued'. DKIM, SPF and DMARC have been configured correctly on websites.domain.com's DNS Zone editor with the correct TXT records provided by email.domain.com. Email delivery section says I need to create a PTR record. WHM is displaying the following: [QUOTE]"The system sends "email.domain.com""s outgoing email from the "123.456.789.0" IP address. The only PTR value for this IP address must be "email.domain.com". This is the name that this server sends with SMTP"s "HELO" command to send "email.domain.com""s outgoing email. 1 unexpected PTR value exists for this IP address:

• xxxxxx.ap-southeast-x.compute.amazonaws.com

To fix this problem, replace all PTR records for "123.456.789.0.in-addr.arpa" with the following record at "pdns1.ultradns.net", "x1.amazonaws.com", "x2.amazonaws.com", "x3.amazonaws.org", and "x4.amazonaws.org":
I am totally lost with that element. I did reach out to Amazon AWS and request a reverse DNS setup for email.domain.com. Additionally, would there be any other reason why the system is unable to send emails? Do I need to edit the DNS Zone on email.domain.com at all? Should it have an A Record pointing to itself? Anything else I am missing here? Any help is greatly appreciated and thanks in advance.