Hello. My name is XXXXXXX. X will try to pick up where your previous Expert left off.

In the case of Comcast in particular, the error you are getting indicates that when the comcast server did a reverse DNS lookup on the sending IP address, it didn't resolve to the host name of the sending computer (this is usually because the PTR record doesn't exist). Comcast requires that all sending servers have a valid PTR record in their DNS zone.

Based on the message header, it appears that you are using McAfee for email protection - and that is the cause of the problem. The "mxlogic.net" server that is being used to send your email is the one being rejected by Comcast. When you are using McAfee to scan your email, it intercepts your outbound email and sends it to a server other than what you would normally use to send mail. This is generally problematic, as is desktop email scanning in general (the number one cause of email corruption).

My suggestion is that you disable McAfee email protection - there are already redundant levels of email protection - one at the server level and the realtime protection on your computer. This will solve you problem with the rejected email and other problems you are otherwise likely to have at some point.

Mike

Please don't shoot yourself. If you do that before accepting, I will not be paid.

This is all making sense then. I am kind of an idiot because I should have realized it from the header.

It's not anything on your computer causing the problem. The problem in this case is that the sending IP address is "blacklisted". And when naive technical people start making decisions, they're usually idiodic and based on heresay vs. facts. The morons at Comcast use what's called a RTBL or "RealTime Blacklist Lookup", which checks the databases of extortionist enterprises like SORBS (Spam and Open Relay Blocking System), who "blacklist" an IP address when/if a single user reports that they have received SPAM from it. Since you (like almost everyone else) share an sending server with many other people, if one of those people has sent spam and it has resulted in being reported, the server is blocked by any receiving entity that checks email against a RTBL until it is de-listed.

I quick check of the IP address of the comcast server sending the message ( qmta12.westchester.pa.mail.comcast.net [76.96.59.227]) reveals that it is, in fact, blacklisted with SORBS.

It's not me that doesn't have it. Only the original Expert that takes your question has the option of chat. If they opt-out and another Expert takes your question, as is the case here, the question converts to this format. So it's not something within my control. I've invested a significant amount of time to provide you with the detailed information that I have, so maybe a simple "thank you" would be more appropriate than telling me that I "need to" get a chat window and that the answer is only useful if Comcast does something about it.

Unfortunately, calling Comcast will not clear it up. In fact, you can expect them to say "we don't use Real Time Blacklists". I spent years designing and implementing one of the largest email service provider networks in the world. So I'm confident in the answer that I've given you, but I can't control Comcast's response or whether they do something about it. In my experience, they will not acknowledge the problem. I don't expect this to help, but I'll give you the report that I was able to pull up on the server with more specifics, since I have an "Email Service Provider"account. It gives the specific emails and computers that originated the offending messages.

SPAM Blacklist Report

I wish the answer was a more pleasant one, but my responsibility is to give you the technical facts. I think the entire "blacklist" business is borderline criminal, but the best I can do is tell it as it is.

Mike

What you describe is consistent with the explanation. When you go through the 3G connection, your are going to the mail server with a different IP address.

I can tell you for certain that the IP address of the sending email server is blacklisted.

What is the name of your computer at home? If you are not sure, right click the computer icon and select properties.

Mike

That's not something I remember you mentioning.

In your chat transcript, you had mentioned emails to 3 people that were getting returned.

For the one that the sender is not receiving, but you are not getting a bounce back for, it will be difficult to verify what is hapenning to the email because whatever that is happens after the receiving server has accepted it. If you don't get a return saying that it wasn't deliverable, then as far as you are concerned on your side, the message was successfully sent and accepted. It's very likely that in this case the receiver has a rule or block of which they are not aware. So we have to concentrate on the one that you are getting the response about.

What happens if you send an email to yourself at comcast from Outlook?

Then the only thing that could possibly be responsible us the individual IP address you are being assigned at your house.

You can do a couple of things to test this. The first is sure to give you fewer headaches if it works.

First Option.

Unplug your cable modem and your router for at least an hour... overnight if you can. Reconnect the cable modem and then your router. This should get a new DHCP IP address from Comcast.

Second Option.,

Call comcast and tell them you need to reset your IP address because it's blacklisted. The main problem with this will be getting someone that understands what you are asking for.

Mike

Actually, that's how you do it.

Just open your browser and go to

http://whatismyip.com

That will give you your external IP address.

Yes, sir... I will be here. I practically live here. The only thing that's kept me away on and off over the past few days is a computer problem I've been having!

Mike