Mails being rejected error 554

Hi,

Receiving this error on mail being sent to Comcast:

SMTP error from remote mail server after initial connection:

host mx1.comcast.net [2001:558:fe16:1b::15]: 554 resimta-po-06v.sys.comcast.net comcast 2601:283:c200:ec00:6e3b:e5ff:fe51:4b79 Comcast requires that all mail servers must have a PTR record with a valid Reverse DNS entry. Currently your mail server does not fill that requirement.

We have a reverse on our mail server, which is sitting in our building on a Comcast connection. Not sure what else I need?

Thanks

MIke

Responses

train_wreck

Gold Problem solver

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610 Messages

9 years ago

Is your mail servers IPv6 address 2601:283:c200:ec00:6e3b:e5ff:fe51:4b79? If so, then both the Comcast DNS servers and dnstoolbox.com both report no PTR. That address looks like a dynamically allocated delegated prefix addres, which is what you would get plugged into any of the leased coax-based gateways. At this time, there is no way to create reverse DNS records for these addresses. Static v6 is coming this year, and i have to assume that v6 PTRs will be available then.

Keep in mind that PTRs for static v4 addresses are different.

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michaelcoffin

New Member

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1 Message

9 years ago

Was this resolved for you Mike? I'm having the same problem, started at the end of July, only impacts outbound emails to Comcast.net recipients.

-Mike

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phantomco

New Contributor

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4 Messages

9 years ago

No, I've reposted it again. I'm not really happy about this and it's becoming more of a problem.

Difficult to believe that they can't set their servers not to reject their own network.

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lonnieb554

Visitor

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2 Messages

9 years ago

I have experienced this same issue. And the problem has been compounded now

to include aol.com email addresses as well as 1and1.com and comcast.net. These

are the ones that I my users are receiving bounce messages from. I suspect there may be

others.

After hours and days of troubleshooting and back and forth with customer service. I found that the PTR records

work best when the IP points to the host server with the following format.

123.123.123.123 mail.domain.com

Since I have several servers on different Comcast subnets, I have been able to experiment with the issue.

I still have the issue with one subnet due to the way that the Customer Service Reps input the info.

I provided them with host names and I wind up with the following.

123.123.123.123 www.domain.com.123.123.123.in.addr.arpa

Some recipient servers (such as aol.com) reject mail if the rDNS returns with .in.addr.arpa in the address.

These servers are looking for only a FQDN or host name in the response.

I would think it would not be so hard to get this corrected but what I have found is that it only gets corrected when it is

kicked up to Tier 2 support level.

Maybe someone in this forum can get this done quicker for me.

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U

user_bb949d

New Contributor

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1 Message

2 years ago

I am having the same problem. However, the above posts are way too technical.

Comcast JUST FIX YOUR EMAIL. We get rejections all the time, mostly send to my secondary Comcast emails. It's been going on for at least a full year. You can't advertise an email service that just doesn't work.

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Comcast_Eric

Official Employee

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29 Messages

Hello @user_bb949d, and thank you for reaching out about having a similar issue as listed above. Can you create your own public post with details as best as you can describe about the current issue we can work more directly with you from please? We hope to hear from you soon!

Like

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2 years ago

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