Mdaemon error

[Jahbriel]

We are having a problem sending emails and receiving emails from one of our biggest clients. Sending and receiving email from anyone else no problem. We are using MDaemon 7.2.2 as our email server. Here is a copy of the SMTP Out log. Can anyone shed some light on what's happening here. I'm trying to send directly to them first and if that fails email is sent out through Verizon SMTP server. The client claims they are not receiving some of our emails and vice versa.

Need Help Urgently

[Big Fish]

Do you have proper reverse DNS records set up for your IP address? You can check it out at www.dnsstuff.com and run the DNS Report test. Yahoo is pretty picky about these things, as is AOL. Any problems with other mail addresses?

It's also possible that yahoo is just overloaded and dropped the connection for whateve reason. Do the messages to through eventually?

[.:MUNDITO:.]

What is ur SMTP server IP address?

1) Have u tested it for OPEN RELAY??

2) Is your IP / ISP black listed at any of the ORBL lists??

I will need your SMTP IP to look into baclists. If you dont intend to give the IP here, please email me the same.

[Zachary]

I don't know this application but Id think it was one of two things
1. already have an smtp server running so its conflicting.
2. the service daemon user doesnt have authority to bind to a port.