Since everyone seems happy to discuss Jade’s email problems in public, I’ll give the likely answers in public as well… If you’d prefer your support requests to be dealt with privately, please use the HELP button, or mail firstname.lastname@example.org
Anyway, email@example.com is not a valid email address. Jade@deardiary.net however, is. Any mail sent to firstname.lastname@example.org will bounce as unknown user. To Jade@deardiary.net however, should be delivered.
In other words, email addresses are case sensitive (on most systems in fact) so you need to make sure you’re giving the right address. Also, you’ll need to check that your private email (which is the one to which we forward any messages) is setup completely correctly on the system.