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Comcast Email Delivery Restarted for TidBITS Subscribers

My sincere apologies to Comcast users who subscribe to TidBITS, purchase Take Control books, or do anything else related to email on our site. For the last month or so, other than an odd week in the middle, Comcast had been refusing to accept any email from our mail server at It took a few weeks before the pattern became apparent, at which point I started the frustrating process of working with Comcast to resolve the issue. Comcast has finally fixed their end, email delivery should resume with this issue of TidBITS, and I hope the problem doesn’t happen again.

Email delivery is becoming more problematic, as ISPs and email providers make their spam filters increasingly restrictive. I’m also tracking delivery problems with AT&T-run email systems and seeing sporadic delivery complaints from iCloud users. And I need to look into some past delivery problems with Yahoo that caused most of our subscribers there to bounce over time.

If you’re interested, here’s what happened with Comcast. At some point in September, Comcast’s mail servers started deferring messages (they’d bounce after 5 days of deferment). This is unusual; generally when an ISP blocks us, there’s an immediate bounce with an error code that explains how to have the block removed. But since we weren’t on any blackhole lists, the standard method of getting removed didn’t work.

Calling Comcast’s front-line support was maddening — it took 20 minutes to get them to understand that I wasn’t a Comcast subscriber and needed to talk to the next level of support, which turned out to be called the Customer Security Assurance Center. Once at that level, the techs at least understood what I was talking about, and while they couldn’t explain or fix the problem (though they tried to blame my server repeatedly), they did promise to escalate my report. But nothing happened, and for several weeks, I’d call in every few days, go through the same troubleshooting process as on previous calls, and get another promise to escalate. Seven calls, all told, and about four hours of repetitive troubleshooting.

Eventually, one of the Customer Security Assurance Center techs called me back to tell me that the top-level support department had determined that our server’s IPv6 address wasn’t resolving properly and that they’d found and removed a block. The IPv6 claim was spurious, as he and the top-level tech admitted when I showed them my results. But the block removal was successful, and mail started flowing immediately. Why this took weeks to resolve, we’ll never know. Amusingly, once the problem was fixed, four of the seven techs called me back to check in.


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Comments about Comcast Email Delivery Restarted for TidBITS Subscribers
(Comments are closed.)

James Wechsler  An apple icon for a TidBITS Contributor 2014-11-03 21:07
Strange. I am a Comcast subscriber, although my email is a gmail address. I received tidbits emails on Oct 6, 13, 17, 20, 27, and 31st.
Nicholas Barnard  2014-11-04 00:49
James. This would've only affected email addresses provided by Comcast and hosted on their servers.

Since you have a Gmail address you weren't affected by this since your email is hosted on Google's servers.
Adam Engst  An apple icon for a TidBITS Staffer 2014-11-04 08:55
Nicholas is exactly right - it was only people with addresses, and only for email sent from our server (so personal mail from me would get through, since I send through Gmail as well).
Carlos  2014-11-03 21:17
It's Comcastic!!

mglazar1  2014-11-03 21:52
Business as usual for Comcast.

I had my lightening-struck DVR replaced 6 times with faulty "refurbished" ones before I yelled loud and long enough that someone finally paid attention and sent me a brand new one, which is still problem-free today - five years later.

But after that new one was sent, I had everyone and his/her cousin calling to ask if my "problem had been resolved" and asking "how satisfied I was with Comcast."

I've learned to always make enough noise to get beyond any company's "second level of incompetence."

After that Peter-Principled group, there are people who can actually make decisions. The first and second levels are only there to discourage you from trying to continue to plead your cause.

Dante's 9 Circles of Hell were nothing compared to a Comcast complaint call.
arjay67  2014-11-04 05:14
My affectionate term for them, for many years, has been Communist-Cast. I had an issue where they were blocking certain websites. Because I operated my own router within the home ALL problems were ALWAYS blamed on that. Even after showing them exactly where the site was being blocked within THEIR network. It wasn't until I had an attorney contact them with threats of litigation that the issue "mysteriously" resolved itself.
john speno  2014-11-04 08:48
What happened to you is terrible, and I've been there many times over the years with Yahoo, MSN, etc. I've found that many ISPs have pages for such situations. For example, this page may have helped:
Adam Engst  An apple icon for a TidBITS Staffer 2014-11-04 08:56
Been there, read that. :-) Yes, all the ISPs have pages like this. Whether or not they actually help is another story.
Congrats to Adam, who had the persistence to put up with Com****'s nonsense. -- Dealing with Com**** myself, I also had difficulty when I tried to remove an erroneously-placed charge from them on my credit card. (Note: Com**** does not even provide service in my area. ) When I talked with one of the many representatives, she noted, "But sir, we do not provide service in your area." -- I tried to explain that what she just said was precisely the problem, but even this discussion did not help resolve the issue. -- I finally resolved the issue, only after explaining the mess to my credit-card company, who promptly made the charge disappear. -- After that phone fiasco, I promised myself to never be a Com**** customer.
Elliot  2014-11-04 16:41
Getting a address is a sure way to avoid Comcast's mishandling of mail to which one has subscribed.

I began using a address for all suscriptions many years ago after Comcast bounced some of that kind of mail. I have never had that problem again.
AlexComcast  2014-11-04 16:47
Hi, I work at Comcast in the Messaging Engineering group. We saw persistent email attacks from a large number of IPv6 IPs at your provider. Given the nature of IPv6, large ranges are grouped together, and your allocated IP was unfortunately within that space. It is not our intent to block your legitimate mail, but to protect our users. In the future, you can refer to our postmaster site ( for more information on our policies.
Nicholas Barnard  2014-11-04 17:12
Hrm, seems like there needs to be a bit tighter filtering on IPv6 IPs then. I guess one of the fixes would've just been to disable IPv6 email sending, since I doubt there are any IPv6 only email servers at this moment.
Adam Engst  An apple icon for a TidBITS Staffer 2014-11-10 13:21
Sorry for the delay in replying - I was at a conference.

In the 4 hours I spent talking to Comcast support techs, this is the first anyone has said about there being a problem with IPv6 addresses at Linode. I run only a single server, and since Linode is a virtual host, it would seem inappropriate to block ranges of addresses. And if that's what you are doing, it would be useful to provide error messages to that effect, and to have your block-list removal work.

I've been to the site many times. It wasn't at all helpful, which is why I had to call the Customer Security Assurance Center reps. Repeatedly.
xandra  2014-11-05 17:01
20 minutes. REALLY!. You lucky SOB.
Have tried to reach a human for 2 months to tell them install was unacceptable (I'd gotten a robo call day after install at 6 AM!, asking for comment, I hung up.)
Adam Engst  An apple icon for a TidBITS Staffer 2014-11-05 18:43
Ach, so sorry to hear it! I got through via the standard phone number pretty quickly, but I also ignored the phone tree, since I knew I needed to talk to a person.
Julian Y. Koh  2014-11-05 20:33
I think there may be a problem with delivery to addresses too. I haven't gotten tidbits since 10/20, and when I first tried to post this comment using my address, I never got the confirmation email either.
Adam Engst  An apple icon for a TidBITS Staffer 2014-11-06 02:38
Sigh... I've heard of sporadic issues, but I'll dig into it once I'm home from MacTech Conference.
Tom Knoff  2014-11-07 10:43
Yes, was having that issue as well. Logged into my account and had to reset email because of the number of bounces. Have no clue as to what that means, hopefully it will resume. Internet provider is Comcast but using a .mac email address.
David R. Calvert  2014-11-09 11:39
I have a .me email and i use Comcast as as my isp, and I haven,t received my tidbits email for the last two weeks.

I guess the email issue is still an issue. No problem with other emails getting through.

Adam Engst  An apple icon for a TidBITS Staffer 2014-11-09 17:55
Yes, looks like several thousand iCloud users bounced in the last few weeks. (insert your choice of obscenity here)

I'll see what I can chase down, but any complaints to Apple you can all make would be welcome.
Adam Engst  An apple icon for a TidBITS Staffer 2014-11-10 13:21
I've restarted delivery for iCloud users now. See
Julian Y. Koh  2014-11-11 07:45
Excellent, thanks Adam!!
Adam Engst  An apple icon for a TidBITS Staffer 2014-11-11 10:46
And they're at it again! %$#&*^*% Comcast is once again deferring all connections from my mail server. Spent 28 minutes on the phone with them today, and we'll see if they escalate it more effectively this time.
Jerry Shields  2014-11-18 00:13
Started for one week. Then none since 11/3/14
Years of no problems! Now no weekly Tidbits.
Very sad when so much energy is utilized in production.
Adam Engst  An apple icon for a TidBITS Staffer 2014-11-18 09:20
I've finally gotten connected with a senior tech at Comcast, so hopefully he'll be able to figure out what's going on and get it fixed for good.
Hi - Hey Adam, sorry to have to report this. For some reason, I did not receive (via the normal, Monday e-mail route) the 17-Nov issue of Tidbits. I have a e-mail address.

I just sent the 17-Nov issue to myself via the suggested procedure in article 13621.

Adam Engst  An apple icon for a TidBITS Staffer 2014-11-24 14:38
This turned out to be human error - in dealing with a stuck queue because of the Comcast problems, a script was modified in a way that prevented it from working and I didn't notice until Tuesday afternoon. That issue did go out, just a little late, and everything should be set again.
Scott Horton  2014-11-24 14:24
I'm having the same problem at No deliver now since receiving the Oct. 20th issue. So far their tech support hasn't resolved the issue.
Adam Engst  An apple icon for a TidBITS Staffer 2014-11-24 14:36
I've restarted delivery for you (you can always do this yourself by logging in to ) and will keep an eye on that domain.
Adam Engst  An apple icon for a TidBITS Staffer 2014-11-24 14:39
For those who were bounced again due to Comcast's errant filters, I think we've worked through it one more time, thanks to finally getting connected with a senior tech. I'll be keeping an eye on it.