The person I contacted for support at AOL says it is no longer possible to use accented letters in AOL Mail. So if I want to write to some in another country and that language uses accented letters like A with an accent it won't work. This must be an error.
If you are accessing AOL Mail from an external browser such as Chrome or Mozilla, you will be able to go into the browser settings and choose your preferred language as French. You can also make sure the spelling on the browser is set up to be in French. This will allow you to write/ correct the accents when writing emails on mail.aol.com. If you are using the AOL Desktop Gold software, the French spell check is not available yet, however you can use the “learn” function for specific words.