It should come as no surprise that my experience as a Comcast broadband subscriber is matching up with many others: extra-sh*tty. Comcast has been flogged extensively elsewhere about its draconian “bandwidth management” techniques – throttling some traffic, blocking others, and now testing new technologies in preparation for implementing this non-neutral network management practice nationwide. And Comcast is not alone in this trend.

My problem with Comcast, however, has had nothing to do with BitTorrent, Skype, Gnutella, or Lotus Notes. It has everything to do with the most important application for which I use the Internet – e-mail.

The problem began a couple of months ago, when those of us in Champaign-Urbana began to be assimilated into the larger Comcast network-borg. I expected an increase in intermittent service outages, but I did not expect my e-mail to stop coming in. But it did, and after two months of sleuthing with Comcast’s evasive and mostly-impotent technical support, I think I have figured out the problem.

My main e-mail address – the one you can find all over this site – is not the e-mail address that I use to technically send and receive messages. Rather, it is a “transparent alias” – I’ve set up a single e-mail address on diymedia.net (mine), and that address is set to forward to whatever Internet service provider I have. Therefore, when I do things like, say, move, I don’t have to send out mass-mails to everyone in my address book, asking them to update my contact information. As far as the world is concerned, I’m phlegm@diymedia.net, and I always will be.

Since I’ve set up this web site, I’ve moved three times and changed ISPs three times. Each time I got a new e-mail address, I simply went into diymedia.net’s administrative controls and changed the ultimate forwarding destination for “phlegm.” Then, I use a mail client (Mac Mail) to pull the messages off my ISP’s POP server and send replies through their SMTP server. To the world, my return address never changes – but the network through which I send and receive e-mail does.

After Comcast informed us in Champaign that we were to set up our new comcast.net e-mail addresses,I followed the company’s instructions, and made the forwarding change here. Everything worked fine for about a week – then, suddenly, I no longer received any e-mail. I have a backup (and very kludgy) webmail interface on diymedia.net (to check messages from the road, as I own no laptop), and I noticed that shortly after my mail stopped I began receiving bounce-back messages from mail.comcast.net. My public e-mail address had been “blocked for spam.”

I can understand how an ISP may suspect this. Because I’m old-school and make my e-mail address not only publicly available, but clickable, it is both a magnet for spam address-harvesting bots and a victim of spam address-spoofing. On regular days, it’s not uncommon for me to receive more than 100 messages, many of them spam. On bad days, I can be flooded with up to 2,000 e-mails in 24 hours, for as long as a week – many of them bounce-backs from a spammer who’s appropriated my e-mail address as his/her “reply-to” contact info for hawking porn, dubious health remedies, and enticements to watch tantalizing celebrity videos that contain a link which actually opens dozens of pop-up advert-windows.

As much of a hassle as this can be, e-mail, relative to many other Internet communication protocols, is not bandwidth-intensive: 2,000 e-mails take up less bandwidth than a single, medium-quality MP3 file, and e-mail messages come in trickles and waves – it is not a constant-use application, file filesharing or streaming media. With prior ISPs, I simply filtered out all the junk locally (Mac Mail is really good at that). Any reasonable ISP has more than enough capacity to handle such detritus. The problem is, Comcast is not a reasonable ISP.

I’ve worked with Comcast tech support repeatedly, getting them to un-block the IP address from which diymedia.net originates (it’s as simple as changing a single line in a text file in the spam-filter on Comcast’s mail servers). Which has worked – but only temporarily. Depending on my inbox-flow at the time, Comcast automatically re-blocks messages from diymedia.net within a matter of hours or days. The problem is thus fixable – but it keeps coming back.

This leads me to one conclusion: Comcast has a metric for what it considers “appropriate use” of its e-mail addresses, and if you receive more than X amount of messages from a single external address in Y amount of time, incoming messages from that address become automatically blocked as spam. In a nutshell, the stream of messages from phlegm@diymedia.net to my Comcast address keeps tripping an auto spam-block rule in Comcast’s mail system.

It is not a block driven by simple capacity – a single comcast.net e-mail address is allocated up to 250 megabytes of storage space, enough for hundreds of thousands of e-mail messages. I get nowhere near that particular limit.

Therefore, this is not a technical issue; it is one of network management policy. Unfortunately, it may simply be par for the course for Comcast. But it’s a troublesome twist on the principle of network neutrality for two reasons. The first is that e-mail, as described above, is not a bandwidth-intensive use of network capacity. If Comcast can’t handle, on average, a few hundred e-mails coming into a single inbox, then its network capacity is much more strained than any of us realize.

The second problem is that Comcast has set an arbitrarily low metric for what it considers to be “acceptable use” of its e-mail service. What if you’re a real celebrity, the kind that has to employ people to answer your fan-mail? Obviously, Comcast is not for you (and on that, at least one of the company’s tech-support folks and I agree).

I spent an hour and 17 minutes on the phone with Comcast one last time today to see if I could get an answer to my question about the metrics of their e-mail and spam-blocking policy. To no surprise, there is no answer. “The folks in the back are really busy,” said the very helpful man I spoke with, who generated yet another trouble-ticket, this time with a note that someone involved in Comcast’s mail network-management department should contact me to discuss this further.

I’m not holding my breath. Instead, I’m unfortunately considering switching back to the Death Star, as Comcast and AT&T are the only two ISPs in my market. AT&T may snoop on me, but since a majority of Internet traffic transits at least one AT&T router, it already does; at least it has the capacity to handle such a simple service.