DNS question regarding MX records

[Gantry]

Having trouble with a certain percentage of emails bouncing for a new domain. I do not have any more info just yet, but I noticed that this domain's MX record is an actual IP address. Is this legal? I though MX records had to point to a hostname...

Thanks in advance for the help

 

[bozo1]

MX should point to a hostname. If not, some sites will bounce mail because the reverse lookup fails.

 

[Gantry]

Hmmm, what percentage of sites bounce mails because of failed reverse lookups? I ask because a had a personal domain with no reverse-dns records for a very long time and never had any problems with bounced emails. IRC and FTP yes, but not email... Not saying it cannot be true, but given that a large % of emails for this domain are bouncing, I don't think it would be because of reverse-lookups failing...

 

[bozo1]

Don't know the percentage but I'm sure it's higher today than in the past with all the spam going on these days.

 

[Abzstrak]

I know that exchange by default will only deliver the email if the reverse lookup is good. I'd assume some others do this as well.

 

[Mucman]

We use CommuniGate Pro and it does would also drop the mail if the MX did not resolve to a hostname... If it does resolve to a hostname it then does some further checks to!