That shouldn't be an issue.

We have 4 Static IP's assigned to our surge mail server.
Two primary domains and associated IP's each host multiple customer domains.
The reverse lookup points to the appropriate master domain.
SPF records indicate that those servers are authorized to send mail for the customer domains.

If you require specific configuration help, you're welcome to contact me off list.

Paul

On Jun 23, 2011, at 10:32 PM, Tom Cross wrote:

> Hi All
> Is there a way around having outgoing mail from our mail server failing to pass reverse lookup done by other servers.
> We are using virtual domains and would like to save the required IP addresses.
> 
> Is there a work around or are we better off giving each Domain their own IP.
> 
> We are a small ISP..
> 
> 
> Tom Cross
> Partner (Synergist)
> HTMLnet 
> 61 2 9288 9488
> 0418 295 336 
>HIDDEN@tml.com.au
> 
> 
>