Move off XP as soon as possible.
Once Chrome pulls security fixes for XP, the moment anyone finds a major bug in Chrome (which happens pretty often), just visiting a dangerous webpage, viewing a page with bad ads, or getting a spam email could get your PC loaded up with piles of malware. This likely means that every one on your contacts list gets an inbox full of spam from you, and if you do anything like internet banking... let's just say don't.
If you only used it for letters and disconnect the internet connection, that would be OK. But not email.