Do you mean the font size changes as you are typing a message, reply, or forward? A user reported this problem on a different mail site, that sometimes after pressing Enter, the next paragraph would use a larger font size. I don't think we discovered the reason for that at the time, but the workaround was to use Shift+Enter to create a line break instead of pressing Enter. (This adds a line break into the current paragraph instead of starting a new paragraph.) Regarding hyperlinks, some mail sites detect and "linkify" them automatically, either in real time or if you save the message as a draft or when you send them. If AOL's site does not have that feature for Firefox users, then unfortunately you will need to use a button to insert the URL as a clickable link. I don't use AOL, but the way this works on other sites is that there is an icon which typically looks like 2 links of a chain, you click that, paste the URL, then click Insert or OK to insert the link into the message.