Handling email address confirmation

When a user sends an email about not receiving a confirmation email, here's the workflow:

1. Copy their email address from gmail (or, better, use https://github.com/ornicar/lichess-gmail)
2. Paste the email on https://lichess.org/mod/email-confirm
3. If the user is found, and a green checkmark is displayed, then the email was set and confirmed. Use the "Email: Confirmed" canned response. Done.

If the user is not found, add the username after the email.

Relevant Gmail canned responses

• Misc: Username?
• Email: Confirmed