This quoted from the latest Langa List newsletter.
Warning! Email *Unbelievably* Unreliable
Email reliability is even worse than I thought. Much worse! At least, that's what our recent worldwide test showed!
Remember a while back when I wrote:
...I'd like to gather a group of volunteers... and send each one a simple non-spam email message, in plain text and with no attachments, from a personal mail account (not a bulk mailer). I'd like to see how many of these simple messages actually make it through the gauntlet of servers, routers, and ISP-based and local mail filters....
Over 10,000 LangaList readers volunteered as test subjects; I conducted the test mailings in mid-November, and sorted and analyzed the results over the holiday break.
The basic test concept was simple: I sent one plain text, attachment-free email to each volunteer. The content of the email simulated normal, safe business or interpersonal correspondence. It contained no deliberate or obvious spam- or virus-filter triggers (e.g. no spamlike components, such as offers to enlarge this or shrink that; no attachments; no viruses; no HTML; no embedded scripts; etc.). The subject line was plain and general, neither designed to trigger nor avoid spam filters.
Plus: the recipients were expecting the mail: They new it was coming, although they didn't know the specifics of where, when or how it would be sent.
Even so, the results were dismal. Some 40% of the test emails didn't make it through!
Think about that for a minute: This suggests that as many as four out of ten of your serious emails--- the sort you might exchange with co-workers, family, friends, business associates, or customers--- may not be making it to their intended destinations.
Or: Four out of ten emails that others send to you may end up lost before you ever see them, *even if you expect the emails and are looking for them!*
There's a lot more to the story. I actually broke the 10,000+ volunteers into four subgroups to simulate different kinds of email (personal, one-at-a-time notes; reply mails; mails with large or small BCC lists, etc) and was able to track how each subgroup did. Some groups lost an astonishing 70% of the mail, even though all the test mails were plain text and non-spam, sent from a normal email client (not a bulk mailer); and even though the volunteers all were expecting a test email to arrive!
A complete description of the tests, and the group-by-group results, are posted at http://www.informationweek.com/story...cleID=17300016