Not possible to cancel from the website
Signed up for the service but haven't received mail for the last 2 years. When I went to the site to cancel, I clicked 'Cancel Mailbox' and just saw a spinning gif and then nothing. No action, no confirmation. But my mailbox wasn't canceled. Nor was the billing. I went next to the chat function for help to verify the account closure. 'AI-Freddy' was his name. He told me that he was closed outside of business hours and couldn't help me. A minute later I asked 'AI-Freddy' if he could help me buy an upgrade and he provided a full menu of options and personal help! But again when I asked about canceling my account, he says that chat is closed. I felt like I was in a Jerry Lewis / Dean Martin sketch comedy. There is an instruction in the chat that tells you to go to the Support Center, which you eventually find in a sub-sub-menu, and which is rolled up instead of rolled down by default. From there you can send an email to try to get your account canceled. The cancellation happened pretty quickly after posting this review, actually, but they really have engineered the process to make it hard to cancel. Bad business.