[tony17112acst]

Wow, you guys are great; thanks for taking the time to figure this out!!

I offer the following updates/answers to the concerns with the previous 4 helpful posts:

You are sending with a non-Comcast From address through their outgoing SMTP server. This might be the cause of the error.

I've had my private domain email as my return address for 10 years and this problem just started with Comcast customers on Jan. 1st. Also, I have 5 other friends/relatives with Comcast that fail and they aren't sophisticated enough to have a non-Comcast return address.

When I check your From address domain, I find using the free http://http://www.dnsstuff.com tools...

I left one thing out in an attempt to not make things more complicated: Since I use my email for ultra critical communications with my tenants and friends, I NEED tonytonini.com email to work NOW! With 50Webs not getting Comcast traffic, I temporarily changed my host to Godaddy (since it's free) and entered an A record pointing to 50Webs for website purposes and left everything else including mail with Godaddy (which is secureserver.net). But I only did this several weeks AFTER the problem started, so it cannot be the problem itself (i assume).

Also, you have a Message-Id which looks like a home email server rather than a normal domain name. "@precision-m4600" looks like a Dell PC to me

I saw that too and have no idea why. Is that something I need to investigate? But I've been using this PC for a long time with no problems receiving Comcast emails - the problem just started Jan. 1st with no changes to any of my settings.

Do you have access to Comcast webmail? If so, then please try sending to that same destination address with your Comcast email address in From using Comcast webmail.

Great Idea! I sent mail@anthonytonini.com an email (hosted by Freehostia) through my account's Comcast webmail and it never got through. I'm expecting NSA's very soon. I even temporarily changed my email client's return address to a my comcast.net despite it not being a problem for many years (the message did not get thru, btw).

you may be on a block list at Comcast. Their support should be able to check this.

Comcast Tier 2 support in the Security Assurance department said they checked all blacklists and didn't see 50webs/Freehostia, but they are not a sharp group over there.

What you need to look for (in case it actually is there and it just hasn't ended up in the bits you've shared with us) is an error code that's usually a three-digit number starting with either a "4" or a "5" .... A "400" series error code usually means a temporary failure, while a "500" series code means a permanent failure.

I wish it was there, but I posted every last thing in the DSN messages. I saved about 20 DSN's for documentation purposes and every last one has a body text of those 4 lines and then the 3 attachments. Comcast support was also looking for the number code.

I'm going to assume that you can actually send messages through your Comcast servers to any other addresses? It's only your own domain that's not working?

Absolutely. I have hotmail, gmail and yahoo accounts to test with, plus all my emails are answered when I send one out.

I realize that you say other family members and friends can't send to you from Comcast either, and I"m going to assume that they're using their Comcast.net addresses, but I'd still recommend testing this from your actual Comcast.net address rather than your custom domain address, just to eliminate this as a possible issue and see if you can get more information out of the DSNs.

Yes, I did change my "from" address to my comcast.net address and get the same failure on tests despite having a non-comcast "from" address for the past 10 years with no problems.

72.167.238.32 | WARNING: The hostname in the SMTP greeting does not match the reverse DNS (PTR) record for your mail server. This probably won't cause any harm, but may be a technical violation of RFC5321

This may be related to me changing my email hosting to Godaddy temporarily the other day, but the problem existed BEFORE I made this emergency change (started Jan 1st and I changed to Godaddy a few days ago).

Your destination domain is anthonytonini.com while the domain you're sending from is tonytonini.com. These are hosted in different places, with only the destination being on Freehostia — and everything does look totally fine on that one, even the SMTP header.

When you say "the domain you're sending from is tonytonini.com" I hope you mean simply what's in the "from" field because with Comcast as my ISP, I only send emails using their Comcast SMTP - I don't think another SMTP would work as I remember them forcing us to use theirs years ago.

The most straightforward question to ask Comcast is: "If the message is being successfully sent to Freehostia, why is the delivery failure notification coming from Comcast?"

OK, I think that's what I'll do now knowing that the server that generated the error is the one that couldn't succeed.

I did a tracert on Freehostia and 50Webs and also saw they had similar IP addresses, in fact, it's how I finally figured out they were both with Liquidnet.

I am a novice compared to you guys, and I also have the feeling Comcast changed a setting somewhere because this all started on January 1st.

So I will call Comcast back and try to get them to take me a little more seriously which I've had to ask them to do several times. I had one rep just start laughing at me because I kept asking "Do your outgoing SMTP servers do any checks for spam/security?" ...to which he said "no" on the 4th time. I just found it very hard to believe that no checks are done with SMPT - He refused to answer the question 3 times so on the 4th time he flatly said "No."