re: email. Common email servers are pretty easy words. Gmail.com, Yahoo.com, Outlook.com, Hotmail.com etc and a huge part of the population is on those 4. Pretty hard to mess up.
Mastodon.social.net, skibiddy.toilet.place etc. Bit more complicated.
Also, email is for boomers. Even in companies, people routinely ignore it (I hate this, but it's true.)