UPDATE Please see the version of this article, the latest malcatcher has its own sendmail replacement, making installation for PHP a lot simpler.
Problem: on development (and test) you don’t want to send out mail. But you /do/ want to test it. You certainly don’t want to be in my shoes when a client called me, telling she recieved dozens of confused and angry mails from users on her site, after I fired up cron on my local development machine. And sent out approximately 3000 notification mails to users, with stuff like “new post for you: “W000t, fieldz0rz developmentz in CCK is workinggggg!”. Not cool.
Problem: when debugging mail, you want to inspect the headers and the source (in case of multipart or HTML mail). Most emailclients are crap for that (and right so: who other then the odd mail/webdeveloper needs to inspect the source of a mail. ever?)
Solution: the brilliant Ruby application named mailcatcher. This is a simple SMTP server, which shows the mails sent to it, in a handy webapplication. The webapplication features debug-tools such as headers, and source displaying.
