Reveal the size of a message by saving a draft.
Although you can't change size limits for messages (these are set by e-mail server system administrators), it's useful to know what they are so that you can stay within them. Staying aware of sizes—an average sized message is around 30K—will ensure that your messages are properly delivered or received.
Sometimes limits on mail size are just practical, not official. For example, if your aunt Mindy is using a really slow modem to download her e-mail messages, you might want to do the courteous thing and send her small messages. This would mean that you'd want to verify the size of the outgoing message before you send it.
You would do this by saving a draft copy of the message and showing the file sizes for messages in your Drafts folder. You'll find the Drafts folder by looking at the Folder List on the Navigation Pane.
Note If your message has a file attached to it, the file size in the Drafts folder may be slightly smaller than when you actually send the message.