For a long time I used Sanford for their company announcement email alerts. That was until they turned it into a pay-for service. Since then I've not found a good replacement so I've hacked up my own.
Yahoo! Alerts will let you setup email alerts based off an RSS feed (its the Feed / Blog alert type). You can give it the URL of any RSS feed and have it email you whenever it changes. So all I had to do was rig up an RSS feed for the companies I was interested in.
Behold my ASX Company Announcements RSS feed.
There are a few other services which syndicate company announcements via RSS but AFAIK mine is the only one to let you specify a custom list of tickers which IMHO is more useful for the typical investor tracking a portfolio or two.
