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Regular Contributor
Posts: 30
Registered: ‎05-13-2006

Email not being delivered

Using smtp.comcast.net, some outgoing email is not being delivered to specific domains. The error message looks like this:
 

Delivery to the following recipients failed permanently:

    foo@foobar.org

============================================================================

                             Technical details:                            

SMTP: host 204.13.88.9: (null)

 

Any idea where I should start trouble-shooting?

 

Email Expert
Posts: 18,241
Registered: ‎04-27-2004

Re: Email not being delivered

This generally seems to mean that the domain is blocking mail from Comcast.

See this thread.
Regular Contributor
Posts: 30
Registered: ‎05-13-2006

Re: Email not being delivered

> This generally seems to mean that the domain is blocking mail from Comcast.
 
Not sure that I agree. My Comcast smtp messages are now going through, but those of my father (also on Comcast) are still being blocked with the following:
 
============================================================================

      This is an automatically generated Delivery Status Notification.     

Delivery to the following recipients failed permanently:

   * xxx@angelflightwest.org

============================================================================

                             Technical details:                            

SMTP: host 66.192.107.205: (null)

============================================================================

So sometimes Comcast is blocked and sometimes it isn't. By the way, when I instruct my father to use smtp.gmail.com, his messages go through just fine.

Visitor
Posts: 4
Registered: ‎12-18-2007

Re: Email not being delivered

I have had a similar problem with my email getting blocked by ISPs overseas.  I made the effort to try to track down the problem, and discovered that the biggest ISP in China is blocking email from COMCAST because they have identified one of the key COMCAST mail servers as a source of spam.  Until COMCAST contacts the Chinese "anti-spam alliance," all mail from this server is blocked.  Here is the link to get the server removed from the list:  http://anti-spam.org.cn/Rbl/Getout/ShowForm
 
Is anyone monitoring from COMCAST?  Any chance to get this fixed so I can use my COMCAST email in my business?
 
Here is some history from my email exchanges:
 

Dear Comcast

 

Your ip addreass is in blacklist Pls remove it

  http://anti-spam.org.cn/Rbl/Query/Result?IP=76.96.30.48&submit=%E6%9F%A5%E8%AF%A2

 

======== 2007-12-17 21:19:30 您在来信中写道: ========

 

Dear SINA Staff,

 

I recently had email blocked by your anti-spam system.  It is essential that I be able to send email to your customers for purposes of my business. 

 

Here is a portion of your message:

 

Your mail server IP address, 76.96.30.48,is rejected by SINA anti-spam system. If your server did not send any spam messages, or has been restored to normal from being abused by spammers, please include the following information in a message to .
We will answer your request by email within two workdays.

 

Here is the requested information:

 

1.  This was sent from my private email address.  The server whose IP address you have flagged is a mail server for COMCAST, one of the larger ISPs in the U.S.

2.  Contact: <removed>

3.  Telephone Number: <removed>

4.  Email Address:  <removed>

5.  Email server IP address:  The server you have blocked is 76.96.30.48, which is the server named qmta05.emeryville.ca.mail.comcast.net.  It is a COMCAST mail server in California.  My IP address is <removed>.  My computer is in <removed>.

6.  Purpose of the email server:  This is just one of the many servers in the COMCAST system.  It is a general email server.

7.  Average number of messages sent from the email server:  I do not know.  I called the COMCAST technical support staff, and they couldnt tell me either.

8.  Error data from rejected mail is attached.

 

I will appreciate your efforts to resolve this problem

 

Regular Contributor
Posts: 30
Registered: ‎05-13-2006

Re: Email not being delivered

 
I'm not sure this is the same problem. Since I can get through to angelflightwest.org using Comcast, I know Comcast isn't being blocked. And at least I'm dealing with an American ISP. ;-)
 
Once again:
1) I can email to angelflightwest.org and the messages are received.
2) My father's emails are bounced with that spartan message.
3) By moving to smtp.gmail.com, my father's emails get through.
 
Pretty black and white - What's going on?
Bronze Problem Solver
Posts: 3,246
Registered: ‎05-12-2006

Re: Email not being delivered



woodp wrote:
 
I'm not sure this is the same problem. Since I can get through to angelflightwest.org using Comcast, I know Comcast isn't being blocked. And at least I'm dealing with an American ISP. ;-)
 
Once again:
1) I can email to angelflightwest.org and the messages are received.
2) My father's emails are bounced with that spartan message.
3) By moving to smtp.gmail.com, my father's emails get through.
 
Pretty black and white - What's going on?


  Actually, it's not black and white. Comcast has many different servers that deliver email to other systems. Some could be blocked while others aren't.
Regular Contributor
Posts: 30
Registered: ‎05-13-2006

Re: Email not being delivered

> Actually, it's not black and white. Comcast has many different servers that deliver email to other systems. Some could be blocked while others aren't.

Perhaps. But my father and I are both in Central California and traceroutes are identical once we get out of the Comcast network.

I'd like to keep this thread on track so I'm returning to my original question. How do I go about diagnosing what's going on? This is a real and repeatable problem. What is the process to get it fixed?
Most Valued Poster
bigchris
Posts: 1,510
Registered: ‎06-10-2007

Re: Email not being delivered

Woodp, I'm looking at your posts and I think i'm a little lost as to what you are describing. What I've gleaned is that you are your father are both Comcast customers and both are trying to send to angelflightwest.org
 
You apparently can email there with no problems, but your father cannot although if he uses gmail he can?
 
Also the rejection message he gets when he tries to email angelflightwest.org is the one you posted at the top which references 204.13.88.9
 
Does that sound right?
 
The problem with this that I see is that the name appears to resolve to ElephantOutlook.com and the IP resolves to coloflorida.com which also has links to elephantoutlook.com (and elephantmx.com)
 
So, confirm what I described above so at least I know if we're on the same page.
Regular Contributor
Posts: 30
Registered: ‎05-13-2006

Re: Email not being delivered

[ Edited ]
> You apparently can email there with no problems, but your father cannot although if he uses gmail he can?

Correct
 
> Also the rejection message he gets when he tries to email angelflightwest.org is the one you posted at the top which references 204.13.88.9
 
Actually, the IP changes. Most recently 66.192.107.205: (null) and 204.13.88.9: (null)
 
> The problem with this that I see is that the name appears to resolve to ElephantOutlook.com and the IP resolves to coloflorida.com which also has links to elephantoutlook.com (and elephantmx.com)


So is that a configuration problem at angelflightwest.org? Or
a rouge DNS server at Comcast?



Message Edited by woodp on 12-18-2007 09:57 AM
Bronze Problem Solver
Posts: 3,246
Registered: ‎05-12-2006

Re: Email not being delivered



woodp wrote:
> You apparently can email there with no problems, but your father cannot although if he uses gmail he can?

Correct
 
> Also the rejection message he gets when he tries to email angelflightwest.org is the one you posted at the top which references 204.13.88.9
 
Actually, the IP changes. Most recently 66.192.107.205: (null) and 204.13.88.9: (null)
 
> The problem with this that I see is that the name appears to resolve to ElephantOutlook.com and the IP resolves to coloflorida.com which also has links to elephantoutlook.com (and elephantmx.com)


So is that a configuration problem at angelflightwest.org? Or
a rouge DNS server at Comcast?


  Neither. Bigchris' "problem" is totally irrelevant. If that IP address was a source of email there could be problems due to the DNS situation, but that's not what we're talking about, that IP address is receiving email. The DNS records in that regard are fine.
  How many emails have you sent to confirm the behavior that email from one of you is blocked, but email from the other isn't? Like I said, there are many Comcast servers that send email, and it's luck of the draw as to which one you get, and they live in several different address blocks. Some could be blocked and others not. The different behavior you're seeing is probably just coincidence due to the luck of the draw.
  If systems think that Comcast's email is too spammy, well, that's just the way it is. Comcast has to either cut down on the spam that's leaking out, or do some sweet-talking to get blocks lifted.
Most Valued Poster
bigchris
Posts: 1,510
Registered: ‎06-10-2007

Re: Email not being delivered



steve-baker wrote:
  Neither. Bigchris' "problem" is totally irrelevant. If that IP address was a source of email there could be problems due to the DNS situation, but that's not what we're talking about, that IP address is receiving email. The DNS records in that regard are fine.
  How many emails have you sent to confirm the behavior that email from one of you is blocked, but email from the other isn't? Like I said, there are many Comcast servers that send email, and it's luck of the draw as to which one you get, and they live in several different address blocks. Some could be blocked and others not. The different behavior you're seeing is probably just coincidence due to the luck of the draw.
  If systems think that Comcast's email is too spammy, well, that's just the way it is. Comcast has to either cut down on the spam that's leaking out, or do some sweet-talking to get blocks lifted.

Steve, let's not dismiss outright something I mentioned as a problem. I'm not saying it is "THE problem", i'm suggesting something I saw I didn't like the look of.
 
Woodp: As Steve asked, how often does this happen? Is it every mail or is there something you can pin down in it's behaviour?
Regular Contributor
Posts: 30
Registered: ‎05-13-2006

Re: Email not being delivered

> Woodp: As Steve asked, how often does this happen? Is it every mail or is there something you can pin down in it's behaviour?

It's every email, and it's been going on for over six months. Every one of my emails goes through, and every other week, when I make dad shut down smtp.gmail.com and try smtp.comcast.net, the email bounces with that spartan error message.

I don't know if it's relevant, but both of us still use Port 25
Most Valued Poster
bigchris
Posts: 1,510
Registered: ‎06-10-2007

Re: Email not being delivered



woodp wrote:
> Woodp: As Steve asked, how often does this happen? Is it every mail or is there something you can pin down in it's behaviour?

It's every email, and it's been going on for over six months. Every one of my emails goes through, and every other week, when I make dad shut down smtp.gmail.com and try smtp.comcast.net, the email bounces with that spartan error message.

I don't know if it's relevant, but both of us still use Port 25


Can you PM me your dads comcast ID?
Bronze Problem Solver
Posts: 3,246
Registered: ‎05-12-2006

Re: Email not being delivered



woodp wrote:
> Woodp: As Steve asked, how often does this happen? Is it every mail or is there something you can pin down in it's behaviour?

It's every email, and it's been going on for over six months. Every one of my emails goes through, and every other week, when I make dad shut down smtp.gmail.com and try smtp.comcast.net, the email bounces with that spartan error message.

I don't know if it's relevant, but both of us still use Port 25


  Sounds like a bit much for coincidence, eh? That's a stumper. It seems like it must have something to do with the content of the message. The content would include your father's IP address; it's possible that it's on a "spambot" list, and that's why the email is being refused. If you want to email me (bakesph at comcast.net) and open up a dialog there are a few things I could check out. My curiosity is aroused. ;-)
 
SMTP: host 204.13.88.9: (null)
 
  Bigchris, Comcast bounce messages kinda bleep.
  I see that there is no error code. Maybe the Comcast server got tired of waiting for a response? Or maybe Comcast doesn't quite grok what went on if the message is refused after the Data?
  It would be nice if the bounces showed at which point in the SMTP dialog things went wrong.
Regular Contributor
Posts: 30
Registered: ‎05-13-2006

Re: Email not being delivered

> Can you PM me your dads comcast ID?

PM was sent. Two more observations:

1) I asked him to try port 587 but he still got the same 66.192.107.205 error message. However, this time I captured the header:

Received: from OMTA08.westchester.pa.mail.comcast.net ([76.96.62.12])

        by QMTA10.westchester.pa.mail.comcast.net with comcast

        id SPpG1Y0030Fqzac5A00H00; Tue, 18 Dec 2007 23:52:54 +0000

Received: from [192.168.1.101] ([69.181.123.215])

        by OMTA08.westchester.pa.mail.comcast.net with comcast

        id SPst1Y00M4ex4fZ3U00000; Tue, 18 Dec 2007 23:52:54 +0000

X-Authority-Analysis: v=1.0 c=1 a=nS36O97Bj3wUElCrIrAA:9 a=WSUfejPYnVaDIwHsvJh5HpFP3bwA:4 a=8pNSdTfqQRAA:10


Westchester, PA?

2) I saw another post here in the forums where frontiernet.net was generating the same cryptically spartan error messages. We both know a guy in Rochester, NY who uses frontiernet.net. Both emails went through without error.

Most Valued Poster
bigchris
Posts: 1,510
Registered: ‎06-10-2007

Re: Email not being delivered



steve-baker wrote:

 
SMTP: host 204.13.88.9: (null)
 
  Bigchris, Comcast bounce messages kinda bleep.
  I see that there is no error code. Maybe the Comcast server got tired of waiting for a response? Or maybe Comcast doesn't quite grok what went on if the message is refused after the Data?
  It would be nice if the bounces showed at which point in the SMTP dialog things went wrong.



Yep.. they are certainly not as helpful as they could be. We're very aware of it and addressing it soon (I hope).
Most Valued Poster
bigchris
Posts: 1,510
Registered: ‎06-10-2007

Re: Email not being delivered



woodp wrote:
> Can you PM me your dads comcast ID?

PM was sent. Two more observations:

1) I asked him to try port 587 but he still got the same 66.192.107.205 error message. However, this time I captured the header:

Received: from OMTA08.westchester.pa.mail.comcast.net ([76.96.62.12])

        by QMTA10.westchester.pa.mail.comcast.net with comcast

        id SPpG1Y0030Fqzac5A00H00; Tue, 18 Dec 2007 23:52:54 +0000

Received: from [192.168.1.101] ([69.181.123.215])

        by OMTA08.westchester.pa.mail.comcast.net with comcast

        id SPst1Y00M4ex4fZ3U00000; Tue, 18 Dec 2007 23:52:54 +0000

X-Authority-Analysis: v=1.0 c=1 a=nS36O97Bj3wUElCrIrAA:9 a=WSUfejPYnVaDIwHsvJh5HpFP3bwA:4 a=8pNSdTfqQRAA:10


Westchester, PA?

2) I saw another post here in the forums where frontiernet.net was generating the same cryptically spartan error messages. We both know a guy in Rochester, NY who uses frontiernet.net. Both emails went through without error.



Ok, thanks I'll look through the logs in the morning for it and see what it says.

As to Westchester, yep your mail can go out of the Westchester or the Emeryville servers, its not regionalized delivery.

Frontiernet were having some issues with us changing our IPs, but we resolved them early December (7th'ish) and I worked with their postmaster to get our new outbound servers on their lists.
Most Valued Poster
bigchris
Posts: 1,510
Registered: ‎06-10-2007

Re: Email not being delivered

Wood, I sent you an email and PM. Can you check it.
 
In looking at the logs it appears your father is not using his comcast.net address as his sending (reply) address, which is fine in theory, but it looks like they are refusing is chosen email address with the message "5.7.1 Sender ID (PRA) Not Permitted". His sending address ends in @mbay.net if that helps.
 
Yes I know this would have been useful in the NDN and I'm hoping we can fix that soon.
Regular Contributor
Posts: 30
Registered: ‎05-13-2006

Re: Email not being delivered

> Wood, I sent you an email and PM. Can you check it.

Yes, and I responded.

> In looking at the logs it appears your father is not using his comcast.net address as his sending (reply) address, which is fine in theory, but it looks like they are refusing is chosen email address with the message "5.7.1 Sender ID (PRA) Not Permitted". His sending address ends in @mbay.net if that helps.

Correct. He's collecting his mail at pop.mbay.net

Intriguing to say the least - Yet I'm also using a non-Comcast POP and return address (woodp.com) and my email's get through to angelflightwest.org ... Something about the way mbay.net is configuring their services?

Most Valued Poster
bigchris
Posts: 1,510
Registered: ‎06-10-2007

Re: Email not being delivered

[ Edited ]


woodp wrote:
> Wood, I sent you an email and PM. Can you check it.

Yes, and I responded.

> In looking at the logs it appears your father is not using his comcast.net address as his sending (reply) address, which is fine in theory, but it looks like they are refusing is chosen email address with the message "5.7.1 Sender ID (PRA) Not Permitted". His sending address ends in @mbay.net if that helps.

Correct. He's collecting his mail at pop.mbay.net

Intriguing to say the least - Yet I'm also using a non-Comcast POP and return address (woodp.com) and my email's get through to angelflightwest.org ... Something about the way mbay.net is configuring their services?
 
If he's really adamant about using mbay.net then he needs to look into whether they'll allow off-net email via port 587 or 465



Yep :-)
 
mbay.net have implemented SPF with a -all flag.
 
;; ANSWER SECTION:
mbay.net.               86400   IN      TXT     "v=spf1 a a:smileyshocked:rca.mbay.net mx:mbay6.mx.proofpoint.com mx:mbay1.mx.proofpoint.com mx:mbay3.mx.proofpoint.com mx:mbay5.mx.proofpoint.com -all"
 
What this means is that no other mta is allowed to relay mail with a from address of mbay.net
 
If your father uses his comcast.net address and tries this again, he should find it'll work.
 
Since this is mbay.net policy and their spf record, there's absolutely nothing we can do about it.

(btw, I didn't get an email from you) 


Message Edited by bigchris on 12-19-2007 01:09 PM
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Re: Email not being delivered



bigchris wrote:

Yep :-)
mbay.net have implemented SPF with a -all flag.

  Nice catch! But...
 
telnet 204.13.88.9 25
...
250 bonito.coloflorida.com Hello [x.x.x.x]
mail from:<x@mbay.net>
250 2.1.0 Sender OK
rcpt to:<webmaster@angelflightwest.org>
250 2.1.5 Recipient OK
 
  Did the rejection come after the Data? Or maybe webmaster is exempt from that check? Woodp, did email sent via Gmail have the same return address?
Regular Contributor
Posts: 30
Registered: ‎05-13-2006

Re: Email not being delivered

[ Edited ]
> If your father uses his comcast.net address and tries this again, he should find it'll work.
We tried it, and indeed, it worked like a charm!

> Since this is mbay.net policy and their spf record, there's absolutely nothing we can do about it.
No, but you gave us the information to go ping the folks at mbay.net. Dad's used that POP account for years and would really prefer to stay with that old email address.

> (btw, I didn't get an email from you)
Hm, I just "replied" from my gmail account which I use at work where I can't access my woodp.com POP address.

In any case, thank you so much for your detective work! I'll let you know what the results with mbay.net are.


Message Edited by woodp on 12-19-2007 11:54 AM
Most Valued Poster
bigchris
Posts: 1,510
Registered: ‎06-10-2007

Re: Email not being delivered

Glad to help. Good luck with mbay.net, although I very much doubt they'll change their SPF records to accomodate since that's an Anti-Spam method they've obviously made a conscious decision to adopt.
 
I'm glad we got to the bottom of it.
Regular Contributor
Posts: 30
Registered: ‎05-13-2006

Re: Email not being delivered

[ Edited ]
> Woodp, did email sent via Gmail have the same return address?

Yes, he used the mbay.net return address as well ... The long version ...

He's been using the mbay.net POP account and return address for ten years now. When Comcast came to his neighborhood, he wanted to keep the return address so we changed to smtp.comcast.net and pop.mbay.net but left his return address with mbay.net. That worked well in general.

About six (?) months ago, emails to several domains started bouncing. There were some RBL problems here and there but all of them were eventually resolved ... with the execption of angelflightwest.org. Not finding an obvious solution, I band-aided the problem by changing him to smtp.gmail.com. That's worked perfectly for months but generates a rediculously long return address with each email:

From: XXX YYY [mailto: xxx.yyy@gmail.com] On Behalf Of XXX YYY [mailto:xxx.yyy@mbay.net]

And users hitting "return" from some domains (aol.com in particular) created a return email to the gmail.com address, not the mbay.net address. Generally, the long return address with two addresses in it created confusion. Thus my desire to return to smtp.comcast.net.

I'm still struggling - There were plenty of RBL problems with smtp.comcast.net that haven't been forgotten. Contrast that with zero issues with smtp.gmail.com - Who knew simple email could get this involved?

As I said, I'll post the results from the folks at mbay.net.


Message Edited by woodp on 12-19-2007 11:56 AM

Message Edited by woodp on 12-19-2007 12:34 PM
Most Valued Poster
bigchris
Posts: 1,510
Registered: ‎06-10-2007

Re: Email not being delivered

As I said a little earlier, does mbay.net not offer authenticated sending via port 587 or 465?
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Registered: ‎05-12-2006

Re: Email not being delivered



woodp wrote:
That's worked perfectly for months but generates a rediculously long return address with each email:

From: XXX YYY [mailto: xxx.yyy@gmail.com] On Behalf Of XXX YYY [mailto:xxx.yyy@mbay.net]

And users hitting "return" from some domains (aol.com in particular) created a return email to the gmail.com address, not the mbay.net address. Generally, the long return address with two addresses in it created confusion. Thus my desire to return to smtp.comcast.net.


   Oh, yeah, I forgot that Gmail forces the Return Path to be whatever your Gmail address is. So all email from Gmail is SPF compatible. Setting a Reply-to: with the other address should fix the problem of replies going to the Gmail address should you need to go back to using Gmail for some reason.
  I don't see a long, crazy From line like that with Gmail, though, it just simply shows my name and Gmail address.
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Re: Email not being delivered



bigchris wrote:
Wood, I sent you an email and PM. Can you check it.
 
In looking at the logs it appears your father is not using his comcast.net address as his sending (reply) address, which is fine in theory, but it looks like they are refusing is chosen email address with the message "5.7.1 Sender ID (PRA) Not Permitted". His sending address ends in @mbay.net if that helps.
 
Yes I know this would have been useful in the NDN and I'm hoping we can fix that soon.


  Can you tell us at which point the rejection occurred? If that (null) in the bounce indicates that it was rejected after the Data, that could be a useful bit of info in future analysis.
  The SPF explanation fits perfectly, but, unless angelflightwest.org have changed things since this discussion started, that's not the answer unless SPF checks are being done selectively. My curiosity got the better of me and I watched a SMTP transaction to the end to see what goes on. Angelflightwest.org is accepting email with an @mbay.net Return Path. That's not surprising since hardly anybody actually uses SPF, and this situation is a good example of why hardly anybody uses it. I'm thinking maybe there are per user serverside filters, and the user inadvertently put the dad's address into a blocklist when he was trying to whitelist it... or something. Not a great theory, I know, it's just something that popped into my head.
Most Valued Poster
bigchris
Posts: 1,510
Registered: ‎06-10-2007

Re: Email not being delivered

[ Edited ]
I believe SPF works at the protocol layer and checks are made at "mail from:" but I need to do more research if I have time tomorrow. I don't want to resort to asking Meng, but it might be the quickest answer. I understand your point about trying a mail session and expecting to be rejected, but I wondering if the SPF rejection might occur later in the dialogue even though the SPF actually failed further up. This is probably completely down to how the MTA developer decides its best to handle SPF failures.

I'm very sure this was the issue. The email address being sent as the mail from: address conflicted with the spf record, especially with the -all flag which denotes the mail can only come from the address in the SPF string. I've seen this problem before with e-vite that also wants to deliver mail 'on your behalf'.

Many people are using SPF records, however very few are using -all since it can cause problems. Rather a shame really.


Message Edited by bigchris on 12-20-2007 09:15 PM
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Re: Email not being delivered



bigchris wrote:
I believe SPF works at the protocol layer and checks are made at "mail from:" but I need to do more research if I have time tomorrow. I don't want to resort to asking Meng, but it might be the quickest answer. I understand your point about trying a mail session and expecting to be rejected, but I wondering if the SPF rejection might occur later in the dialogue even though the SPF actually failed further up. This is probably completely down to how the MTA developer decides its best to handle SPF failures.
 
  You might remember that I previously checked down to Rcpt To. But then I checked right through the Data, which is as far as it can go. Not rejected. I checked from Demon user address space which is unlikely to be whitelisted for stuff like that. Yeah, you're right that it's up to the admin of the MTA as to how they want to handle things. Some places go along right through the Data and won't reject anything until after the Data. Makes it harder to do dictionary attacks.
  You're not going to tell me when that email you found in your logs was rejected? C'mon.
 
I'm very sure this was the issue. The email address being sent as the mail from: address conflicted with the spf record, especially with the -all flag which denotes the mail can only come from the address in the SPF string. I've seen this problem before with e-vite that also wants to deliver mail 'on your behalf'.
 
  Like I said, it makes perfect sense. But I don't see that behavior in my tests.
 
Many people are using SPF records, however very few are using -all since it can cause problems. Rather a shame really.
 
  Many people are publishing SPF records, and, unlike these guys, most (like Comcast) publish a lame version. But publishing and using aren't same thing in my vernacular; using is when you make decisions about accepting email based on SPF records. There's not a lot of that going on. I'm sure many Comcast folk use smtp.comcast.net to send email with a Return Path pointing to a non-Comcast email domain. SPF breaks that. SPF breaks forwarding unless forwarders ignore the current standards and rewrite the Return Path. SPF was originally touted as a solution to spam until the shocking discovery was made that spammers were capable of publishing SPF records. Umm... I guess I got a little carried away. Sorry about that.