I've encountered something new for me and could use a little advice.
I recently set up Exchange for a small client and pointed their MX record to their public IP and all works well. However, they have 2 domains and I pointed both MX records to their IP -- they only host e-mail for these 2 domains - web site is elsewhere. So I have mail.abc.com pointing to their IP address and mail.2abc.com pointing to their IP address. Mail comes in fine and I have their default e-mail addresses in Active Directory set up.
However, I started getting bounces because their ISP didn't have a reverse DNS pointer. I contacted their ISP and learned that there can only be 1 reverse DNS pointer per IP address (makes sense, now that I think about it). So right now a reverse DNS lookup of their IP address returns mail.abc.com -- how do I handle the mail.2abc.com record?
Thanks in advance for the replies.