Do not communicate and promote e-mail company guidelines (e-Standards) only through e-mails, or as a labor formality.
Use all communication channels available inside the company to sensitize and reinforce employee's commitment on this issue.
Don’t expect them to learn how to use better e-mail only with the manual of norms and procedures.
Employees need ample and detailed training on its risks, their rights, responsibilities, and the consequences of the improper use of this communication tool.
They need to know as well how much is the impact of some witten messages. Discussions or "clarifications" among teamwork could take many more time (and costs) than a phone call or a face-to-face meeting.
Don’t expect a single individual or department to be responsible of overseeing compliance to corporate policies on the use of e-mail. This is not strategical.
All managers and supervisors must provide support to monitor and model employee’s behaviors because otherwise good practices will not be adopted in a good will manner.
Remember, some bosses usually are the main rule-breakers, and their inconsistency doesn’t make it easy for employees to adopt e-Standards.
Bosses and others supervisors levels have to be first accomplish e-mail company guidelines. They are responsible for setting good examples.