For HTML format messages only, it is possible to set up styles, much as they might be set up in a word processor. The following can be set:
Once created, styles can be selected very quickly by using CTRL+SHIFT+NumberKey, eg CTRL+SHIFT+2 or from a drop-down list.
NOTE that these are TEXT STYLES, and will only apply to selected text, or from the cursor position when new text is entered if there is no selected text.
Click on a HotSpot on the image below for further information.