Copying text from Microsoft Word documents can sometimes corrupt characters, and produce a ? rather than the desired character.
To avoid this, copy text from a different type of document, such as a PDF, or to write the email from scratch on Classlist.
If you have the Word document saved on your PC, click Save As, and you can choose to save as a PDF or a Rich Text document which should eliminate this corruption. If you want to use all the text in the document, why not just add it to your announcement as an attachment? Use the paperclip icon at the top of the text box of your announcement to attach a document.