It appears like majority of the people I meet are a fan of "archiving". Creating an archive of photos, music, movies, TV shows - everything.
We love to keep things that would become a memory some day. Who doesn't have a notebook from 10 years ago hidden somewhere on the shelves or under the bed? I bet no one. That is a natural urge.
We apply the same intuition to our written correspondences as well. I have seen people create an archive directory for their emails which then has a number of subdirectories to categorize them, such as:
~ Archive |- Project Alpha |- Know-how |- Project Beta |- Management |- Product Development
This looks like really neat and organized, and it takes motivation to keep it that way. The question is, how many times have you used this structure?
I suggest using a more simple approach:
Act & Archive vs. Delete
Whenever you receive an email to your inbox you need to decide:
What should I do with this information?
Is it an email chain that has a dozen emails, with no added value? Delete it.
Is it an email chain that has a dozen emails, but this one has an important piece of information? Archive it.
Do you need to take an action on it? Leave it in Inbox, move it to Archive when you're done with it.
You simply need 2 folders for this approach: Inbox and Archive.
It's unbelievable how many emails you can simply delete and never regret it.
If you want to search for an old conversation, simply search the single Archive folder you have. It doesn't really help to sub-categorize the archive if you won't go into a folder and manually scan the emails. Searching doesn't matter if it happens in a single folder or in all folders, unless you give a very generic search term such as "bugs". If that's the case, I suggest you practice your searching skills with better keywords.
Trashed emails usually get deleted permanently at least after 30 days. This gives you a reasonable amount of time in case you need it afterwards. After that cool-down period if you still don't need it, you'll probably never need it.
Clearly, we have so much information flow during our era that it's getting increasingly easier to get distracted. This has been the simplest and most effective way to avoid this for me when it comes to emails.