Looking for ways employees/companies/individuals limit incoming
emails?  For example, unsubscribing to junk lists, putting "eom" at
the end of a message, etc.

What method(s) are most effective?

Thank you...you ROCK!

Try with...
- filters
- a Gmail account (https://mail.google.com/)

There are numerous ways to limit the emails you receive, depending on
how much control you have over the email system.  I assume the reason
for asking is because you are receiving lots of spam and/or viruses. 
If you are an individual:

1. use mailinator.com to use and generate junk email addresses when
you subscribe to websites.
2. create multiple email addresses with your ISP then autoforward
those other email addresses to your main email account.  e.g. an email
address for mailing lists (john.smith.lists@isp.com) autoforwards to
john.smith@isp.com.  Thus, if an email address is getting spam it is
easier to abandon an email address and you need to resubscribe to
fewer sites.
3. see if your ISP supports server-based spam filtering.  e.g. 
Tiscali in the UK does this.
4. Hotmail accounts can classify all email as junk unless the email
address is in the address book.

If you are an employer:

1. it is common to have procedures and/or rules that state the email
system is for work-related purposes only.  Therefore, any employee who
is drawing lots of spam to their inbox or spends a lot of time
emailing friends can be dealt with through the disciplinary
procedures.
2. ISP-based spam filtering again.
3. company email system reads the headers from the ISP and rejects all
emails from aol.com, hotmail.com, etc.  http://www.spamcop.net/ or
http://spamassassin.apache.org/ might have this feature but they also
have other email filtering features (dns-based open-relay/spam
blocking, spam/virus recognition and blocking, etc).

I suspect that your troubles are more related to time management than
genuine spam difficulties. At least it has been in my case!

I get over 3000 emails a day.

I use a number of different spam filtration programs to cut down on
the chaff, but I've found that it really is a matter of management
more than technology.

I have only one suggestion for you:

Only check email TWICE per day. No more.

I work on the Internet... so it can only be assumed that I live for
the next batch of emails to come in every 5 minutes. But that's not
the case.

Unless you make the decision to handle email like a "task" rather than
a phone call, you're in for a highly unproductive worklife.

I check email once in the morning, and once in the afternoon.

The first thing I do in my day is to check email and handle any
problems waiting there in my inbox. After lunch, I do the same thing.

After checking my email and handling the problems therein, I turn my
email client OFF. I shut it down... EXIT... and all that jazz!

NOTHING is worse for productivity than INTERRUPTIONS.

TURN OFF OUTLOOK.

Check email only twice per day, and you'll see a MASSIVE change in
your productivity. I have!

-Nathan Anderson
<a href="http://www.artofthecontentsite.com/">Art of the Content Site</a>