I was talking to a friend and found out that he didn’t know the following really useful Gmail addressing tips. I figure if he didn't know these, then there are probably of other people who don't either. So, in case you’re in that group, here goes …
Tip #2: Filtering with aliases. If you use the technique discussed in Tip #1 you can then use the TO: address in a filter. For example:
If you don’t include the “to:” in the search query you’ll also get a match if the address with the alias is in the body of a message (for example, forwarded messages or a reply could have the original recipient address quoted). Note that partial matches, e.g. “your.username+any”, which you can’t use with “to:”, will match with firstname.lastname@example.org but not email@example.com.
Tip #3: Using periods. Even though Gmail addresses often contain periods the service, in fact, completely ignores them. Thus, firstname.lastname@example.org is equivalent to email@example.com, firstname.lastname@example.org, or even email@example.com.
Tip #4: Using "throwaway" addresses. An interesting hack with Tip #3 is using it with aliases for identifying “throwaway” addresses. Thus, if your email address is firstname.lastname@example.org you might decide to use addresses of the form email@example.com for signing up for subscriptions and offers. Once the sender annoys you or the address winds up on a spam list, you can just filter it straight into the bit bucket.
If you’ve got any more tips for doing neat things with Gmail addressing (or anything else with Gmail) please let me know.