–Forward messages list: select the mode of forwarding messages: Inline or As Attachment.
–add extension to file name checkbox.
–Auto Save every N minutes checkbox.
–Confirm when using keyboard shortcut to send message checkbox.
–Add link previews when pasting URLs checkbox.
Spelling
–Check spelling before sending checkbox.
–Enable spellcheck as you type checkbox.
–Language options: select the available languages for spell checking.
HTML Style
–Font and Size lists: select the font and size of the email text.
–Use reader’s default colors checkbox.
–Text Color and Background Color buttons: adjust text color and background color in emails.
–Restore Defaults button.
–Use Paragraph format instead of Body Text by default checkbox.
Sending Format
–Automatic: If no styles are used in the message, it will be sent as plain text. Otherwise, it will be sent as HTML with a plain text backup.
–Both HTML and Plain Text: the recipient's email application will determine which version will be displayed.
–Only HTML: some recipients will not be able to read the message without the plain text backup.
–Only Plain Text: some styles will be converted to the plain text alternative, while other types of design will be disabled.