What are some email addresses that would produce the following mesage in Gmail?

Not that I am aware of. But the advice (0 for O, l for 1) is well known in the email security industry, so this advice is nothing new at all.

In fact, it isn’t just restricted to 0 and O – there are dozens, even hundreds, of foreign language characters in the Unicode list that look like a O or a 0, but have an entirely different character identifier.

Why do you ask?

Because of this OP.
https://www.fluther.com/210018/how-does-one-move-on-from-the-following-message-in-gmail/

How do you get rid of the message, (since there is nothing like “ok” anywhere in sight) and start with the composing?