Could not deliver to the following recipient. Remote host said: 554 5.7.1

I have several companies each of which uses a dedicated server in a data center in AZ. We have enterprise class email software. Many of my outbound email messages sent from my Outlook account via a Comcast Business internet connection are rejected by the receiving mail server because the Comcast-assigned dynamic IP address of my network is blacklisted on Spamhaus (by Comcast). This appears to be a change in the terms of service and makes your service worthless to me. What can be done to resolve this or should I just cancel this service?

Thanks.

Responses

Accepted Solution

Comcast_Jon

Administrator

•

1.5K Messages

12 years ago

Hello pynchros,

Welcome to the forum.

The community would like to assist, but could you clarify few information for us?

1. Are your emails being rejected by some or all your receipients?

2. For your outlook setting, are you using pop3,imap or exchange?

- If pop3 what are you using for the out going mail server?

Thank you

0

pynchros

Visitor

•

4 Messages

12 years ago

Thanks, Comcast_Jon:

These e-mails are rejected by some recipients - the affected destintations belong to a company that has a number of domains hosted at the same location. This makes me believe that they (the company or the ISP) are using SORBS-DUHL as part of their SPAM checks as it is specifically having a problem with the Comcast Dynamic IP address that is added to the header not the IP address of my mail server.

The two accounts I have tested (and which are rejected) both use POP3. The SMTP server is my corporate SmarterMail server, mail.symantry.com.

0

Comcast_Jon

Administrator

•

1.5K Messages

12 years ago

pynchros,

Thank you for the information.

I've checked the status of your domain on mxtoolbox.com for any common blacklisting and it came back clean.

This points the troubleshooting path toward asking recipient domain's server admin for checking their filter list.

The reason being all of Comcast's dynamic IP addresses are intentionally listed. Its intent is for generally usage and not meant for specific which our static IP range are for.

This is what I suggest for the troubleshooting.

1. Please if possible post your email header so we may discern it.

2. If your email server has webmail access, please try to send it from there for a test.

- This test will assist in discovering if a particular email address on your domain has been blocked along with the domain itself.

Thank you

0