Your gmail address is fairly flexible. Suppose your address is foobar(a)gmail.com You would receive mail sent to - fo.obar(a)gmail.com - f.o.o.b.a.r(a)gmail.com - foobar+flotsom(a)gmail.com - foo.bar+flotsom(a)gmail.com So if you sign up at amazon.com <http://amazon.com> with your foobar(a)gmail.com e-mail account, you use foobar+amazon(a)gmail.com. Then you check the address that your spam was sent to, and if it is from foobar+amazon(a)gmail.com (highly unlikely as it is), you can take action from there, including sending an upset letter, closing your account with them, and automatically nuking all of the e-mails sent to that address with a filter. It's also useful for categorizing mail by address. Want to make sure you don't miss an important e-mail from a friend? Give them foobar+jeff(a)gmail.com, and set up a filter to automatically star messages sent to that address. This doesn't work quite as well on mailing lists. Suppose you signed up here with foobar+wikitech-l(a)gmail.com. Then, everytime you want to post to the list you need to go into your settings and change your reply-to address before and after you send the mail. If you're already typing the message, you have to open a new window and set it (or save your e-mail as a draft and navigate away from it). I might put together a greasemonkey script that makes this functionality more accessible by adding an extra field before To: that says From: If you use an external client that supports this functionality, Gmail will let you send mail from any address via an SMTP server. It's not that it's a bad feature, just that it's inaccessible (likely intentionally). /Alterego On 7/18/05, Jamie Bliss &lt;astronouth7303(a)gmail.com&gt; wrote: