Seek training for yourself and others on a regular basis. Many people spend a good portion of their days only in e-mail. You might find that a mini-session on using rules, managing folders or creating groups will be surprisingly well attended and can be repeated from time to time. E-mail raises issues on a regular basis. You will want to keep apprised of virus and security issues.
Encryption is a growing and important issue.
Again, a great resource on a variety of e-mail issues is Jerry Lawson's excellent The Complete Internet Handbook for Lawyers. A helpful book on the e-mail program you use or the occasional foray into Help screens can be especially rewarding and give you new ideas, techniques and tools. E-mail is fundamentally a communications tool and like all communications will change and evolve steadily. Great e-mailers are made not born. It will take some time and effort, but the rewards are immeasurable.