As you well know, there's no such thing as a happy sysadmin, but there are some things that you can do that will make them even grumpier than usual. A big fat juicy email promotion has the potential to do just that. Here's a couple of suggestions on how to make them run far smoother, based on a couple of recent bad experiences.

1. Spread the mailout. This means more than splitting half a million email addresses into 3 and sending them an hour apart. Also, consider when you're sending them. If you send hourly, but start at midnight, then the likelihood is that the server's going to see the load from the first 10 or so at the same time. Sending 50,000 an hour will generate an appreciable extra load on any server. Sizing one to support 250,000 in one go will result in a major waste of resources for the other 29.75 days of the month. An expensive waste!
2. Make sure the link in the email is to a static page. A link to a complex search ( yes, this did happen! ) will require 10-15 times the amount of processing power to deliver, which cuts your server's capacity by that amount... instead of breezing thousands of pages a minute, you're mysteriously below 100, and your servers are melting before your eyes.

This will make your email campaigns far more effective, keep your sites more responsive, and may even get a grunt of approval from the SysAdmins cave. But don't hold your breath...