Undelivered e-mail says my DNS is broken

[JVW]

One of the employees received this message when they tried to deliver an e-mail:
553 5.3.0 Mail from xxx.xxx.xxx.xxx rejected--your DNS is broken and I cannot tell who you are.
Anyone know what I need to look at? I have checked my server and it seems fine. The employee can send to anyone else.

Thanks ;-) Thanks,
Vince

 

[JVW]

WE have noted two possibilities so far:
1. The ISP does not have a reverse lookup zone setup to the IP. (*Specifically for us*, we had one, but we needed to add another for our mail server.)
2. May be getting rejected, because the IP address has been "labeled" as a spammer. To check, go to mail-abuse.org. This will give you information to check out your IP. ;-)

Thanks,
Vince

 

[JVW]

Turns out the ISP needed to add the reverse lookup and that was it.

Vince Thanks,
Vince