All sorts of problems come with an e-mail box that gets too large. Bloated e-mail boxes are a technological and administrative headache. Self-discipline over the size of files that we store or that we attach to e-mail is part of good discipline and e-mail courtesy.
One technique for controlling the size of files is to use lower-resolution graphics wherever possible. For most uses, the lower resolution version looks the same on the page even though it takes one-tenth or even one-hundredth the space. Your communications team should have low-resolution versions of all your logos and graphics. These should be used for all e-mails and internal documents such as meeting minutes and presentations. Make sure your staff know where to find the approved versions of all your official graphics.
A second technique is to scrupulously avoid attaching unnecessary graphics to your e-mail in the first place. Graphics in your signature block are specifically discouraged. While some people think that they add a "personal" feel to the message, they go out on every e-mail, bloating both your and your readers' e-mail boxes. Furthermore, they often fail to display correctly, especially if the message recipient uses a different e-mail program than you do, and frequently cause the message to get trapped in the recipient's spam or virus filters. Keep graphics to an absolute minimum in e-mail.