I was exchanging emails with a friend at another company a while ago.
We got to talking about email.  It turns out that he gets about seventy
-five to a hundred emails a day.   I asked him how many unread emails in
his Inbox he has right now.  He said; "26"  How many total? “  Again he 
said "26"   I asked him how he managed that.  He responded; "A few email
 tricks."

I asked him to expand on that thought.  Here is his response:

The Collected email wisdom of Steven Michael Young (used with permission).

"One thing that you need to tell people:  For me, managing my email is 
not a matter of choice.  It’s a matter of professional survival.  If I don’t
stay on top of it, it gets on top of me pretty quick.  I learned a long 
time ago that O.E.  ("Outlook Express"  - his email software - JH) keeps 
absolutely everything you ever get or send.  I mean, come on!  I’ve 
learned to be pretty ruthless about deciding what’s important to me 
and what isn’t. 

 
1: I have a subfolder of my Inbox.  I've changed the name of it 
over the years, but it's purpose remains the same.  It holds all the 
email I need fast access to, without junking up my Inbox.  As soon as 
I’m done with an email, I put it in there.  Later I go to this folder 
and I file emails or delete them.  The only thing I want in my Inbox 
is unread email, and un-responded email.   Even with that, i [sic] 
have about 30 or so emails in my Inbox at one time.  

2: I don’t keep responses, of responses, of responses, of responses.  I 
only keep the last one and dump the rest.

3: I don’t keep out of date [emails] in my Inbox.  It goes in a folder.  
Once a week (usually just before I go home) I go through the emails 
that are older than a week and file them. Lately it’s been once every few weeks.
 
4:  One more thing.  I sometimes don’t respond to an email right away, 
but if that’s the case, I at least let the sender know that I got it 
and looked at it.  I just send a quick response like "Hi, I read your 
email.  I’m doing some thinking about it (or looking into it).  I’ll 
send you a detailed response in a little bit."   That lets the sender 
know I’m there with it, and let’s me respond when I’m ready.

 
Almost nobody here does what I do, except maybe [one of the executive 
assistants], who taught me most of this.  She is famous for her 
ability to keep her cool when everyone else is loosing theirs.   
I decided I could use some of that, so I find out how she does things.

It doesn't seem to matter what e-mail software you use.  It works 
on any of them. I've done this with GroupWise, Mozilla Mail, Pegasus and OE.

So there you have it for what it’s worth.  Hope it helps your folks.

‘Steve