What the specific error was in you case is a matter for speculation, but there are some things you may or may not know and I have a suggestion to reduce the possibility of its recurring...
- Composer in Apple Mail creates messages in Rich Text Format by default, so there really is no need to create the RTF in Word to retain the formatting, unless you are using formatting beyond the rather basic set supported by Composer.
- Some recipients have their email client set to use plain text to save bandwidth on slow networks. The only way send a formatted message to those persons is as an attachment (which ends up taking even more bandwidth than a formatted message.)
- The RTF formatting as seen on your computer is the result of invisible tags embedded in the text that tell the receiving application how to display the text.
- Formatted text copied directly from the Word screen into Mail another app may not capture the tags or all of the tags.
- A missing or incorrectly copied tag can cause serious havoc with the format when it is opened in another app or device.
- Create the message in Word and save it as an RTF, then send RTF file as an attachment, and even recipients with their email client set to plain text only will see it ass the fully formatted document you intended.
