1) If you don't really need a reply to the message you send, say so. Some people like to put NRN (no reply necessary) in the subject line.
2) Make new Mailboxes (Apple Mail) or Folders (Webmail) to organize your Inbox. Then you can either drag a message to it from your Inbox, or set up a Rule or Smart Folder to direct incoming messages directly to that mailbox. We see lots of folks out there with several thousand messages in the Inbox who then have trouble finding what they need. If you need help with this, let the Help Desk know.
3) You might want to use the blind copy field for sending a copy of outgoing messages to yourself. Then they show up in your Inbox, where you can more easily direct them to folders you've created instead of scrolling through the hundreds of Sent Mail messages to find the one you want (or using the search bar to locate them). You can also empty your Sent Mail folder now and then to keep things nice and tidy.
4) Manage your time by scheduling blocks for reading and returning email. Yes, it's nice for you to be accessible and seen as responsive, but how many e-mails in a given day are truly urgent enough to displace more important work you'd hoped to accomplish? We all know what a time drain e-mail can be, and the constant arrival of messages in our Inboxes can be a real distraction. Take control of your e-mail habits and you'll be in a better position to focus on your high priority tasks.