Click OK . When you enable HTML in Internet Mail and News, all messages are saved in HTML format. If the recipient's mail or news program reads HTML formatting, the message appears in the correct HTML format when they open it. If the recipient's program does not read HTML formatting, the message appears as plain text with an HTML file attached. The recipient can view the attached file with all formatting by opening it in any Web browser.
Plain text is simple text with no special formatting.
MIME provides a standard for mail programs to encode and interpret data. This option allows the use of special characters, such as a character with an accent mark. Base64 is a MIME-encoded file transfer method for sending binary messages as text. If this check-box is cleared, these characters are encoded. Uuencode Uuencode is a way of converting binary files into plain text that can be inserted into a message, sent, and converted back to a binary file by the recipient.