Issue sending to a few domains

[acollard83]

I am having an issue with users trying to send to a couple domains. I get the following error, 451 4.4.0 Primary target IP address responded with: 421 4.2.1 Unable to connect.

I have verified we are not on any blacklists, rDNS is properly setup, SPF records are added. I also tried telneting from the server to that mail server and it just dropped the connection before I could even connect.

I am able to send email to that domain from my gmail account.

The main domain in question that we are having issues with is broadsoft.com. My mail server is smtp.tekservicegroup.com

 

[Zelandakh]

Does your ISP list you as a dynamic / DHCP IP address?

 

[acollard83]

No. We are the ISP and that subnet is assigned and listed as a static. It is not listed on the PBL.

 

[58sniper]

They are manually blocking you.

Do you have your Tek-Tips.com Swag? I've got mine!

Stop by the new Tek-Tips group at LinkedIn.

 

[acollard83]

That's what I thought. I've tried changing IP's to no avail. They must be blocking our entire IP allocation. Thanks. They are using mxlogic if that helps.

 

[Zelandakh]

For your outbound domain name, do you have a matching A record with an IP address? I've seen some older email gateways rejecting if you don't.

 

[acollard83]

Yes A record matches the PTR.

 

[Zelandakh]

Telnet to one of those hosts and see if you get any additional information

 

[acollard83]

Telnet kicks me off right as I connect. Also, some emails get through after sitting in the queue an hour or more.

 

[acollard83]

All the domains that are being blocked/delayed uses mxlogic.