Write effectively so your message gets across. Write plain text Write your e-mail messages using plain text only, with blank lines separating paragraphs. Although most modern e-mail programs allow you to use different fonts, colours and other adornments, resist the temptation to use them. Limit lines to 72 characters Your reader's e-mail program might not support line wrapping, so it's up to you keep lines short. Even if your e-mail program wraps lines so you can read them, your reader may not be able to read it.
Long lines cause lots of problems for many readers.
For some, the lines will be wider than their window, so they have to scroll to read each and every line. For others, the long lines will be truncated when they print the message. And for an unlucky few, the ends of the lines won't appear at all. Well, most readers will be able to handle 80 characters, but if they quote your e-mail back at you, it will often have some extra characters added to the front of each line. Limiting yourself to 72 allows for these extra characters.