Andrewza

have the PTR records for both IPs point to the same name won't work, because then it'll try looking up the A record for that name and find for two of the three cases it doesn't match.

Though I've not seen a problem as long as the machine's IP has a PTR record pointing to a name, a name that has an A record pointing back to the machine's IP.

buh, misread, nevermind, above still applies though.

[Edited by Andrewza - 10/8/2002 5:37:57 PM]

what would scooby do

Just wanted to know how most companies handle reverse lookup problems on smtp mail, when you have multiple outbound smtp gateways and hundreds of domain names.

Inbound mail is not an issue, but we want to avoid destination email systems rejecting our email due to reverse lookup problems.

Currently we are using an ISP's "smart mail host" - is this the best/only solution??

what would scooby do

BTTT

"was the question too difficult"

stevencotton

No, but you don't mention what the "reverse lookup problems" are

Steve.

Andrewza

I send out quite a lot of mail from some of our servers (20K subscriber itv-f1.com newsletter for one) and the only problems I've seen is where the machine had no reverse DNS, all our mail appears from itv-webmaster@itv-f1.com, but mail appears to come from a machine in another domain entirely.

what would scooby do

yeah - more and more email systems check that the sending domain resolves back correctly to the IP address i.e.

mydomain.com = 10.1.1.1

now we have 3 servers in different parts of the planet all sending out email from mydomain.com - each with a different IP address, and therefor reverse lookup will fail on two of them

dsmith

Surely you just need PTR records for all possible IP addresses ?

Multiple PTR records can resolve to the same name

Deano

what would scooby do

Yup - we tried that and still had some email bounced back to us!! - still trying to figure out why!

orbv

so two machine wrx and sti sending and receiving email for the domain scooby.net.

Both wrx and sti require A records for themself.

Incoming
mx for scooby.net pointing to both wrx.scooby.net and sti.scooby.net.

Outgoing
Dont need anything except machine using making sure machine uses its name within the EHLO instruction.

what would scooby do

cool