I was recently confronted with the task of sending out a mass mailing. Now, there is nothing terribly exciting about that, but due to the delicate nature of the mailing, I had to track responses to the mailing itself: how many bounces, who answered, etc. (I know, I know: that kind of stuff is usually a secretary's job -- at best --, but this time I was the secretary.) The message was phrased in such a way as that recipients would be very interested in acknowledging its reception. A piece of cake, you'd say, and so did I, so I enjoyed a piece supplied by the best pattissier in town. The Pralinentorte you see here has enough calories to nourish a small country for about a week, and it is truly scrumptious -- I digress. This mass mailing wasn't directed at housewives (no offense to housewives) but to businesses -- most of them small -- with whom the organization I did this for kept regular e-mail contact, or so I thought. In said mass-mailing, most of the addressees the mail went to represented smallish organizations who have their e-mail hosted at one of the sundry free-mailers or local ISPs. 14% of the messages failed at the first attempt. Of those, 37% bounced with a 55x code indicating target mailbox is over quota or the accepting mail server can't relay onwards. 19% of the addresses where rejected (no such user), and 44% were unroutable (e.g. because the domain name no longer existed). After 24 hours, 22% of the messages hadn't yet been delivered (we kept getting warnings about non-delivery). Of the messages that got through unharmed, only 40% were reacted upon within 36 hours. Larger organizations typically maintain their own e-mail infrastructure, and they have system administrators who (sometimes) know their job. Experience shows that there is seldom a problem to get an e-mail to such an organization. (Whether it is then read by the correct party is a completely different topic: I'm simply talking about successful SMTP delivery at this point.) Small joints or one-man-shows don't have that luxury, can't afford to have it, and don't need it, because there are dozens if not hundreds of Internet Service Providers who provide that service for a typically very small amount of money. The operative word here is provide. Do they really provide service? E-mail still isn't a piece of cake.