Typically inside a company (like a bank) there's an email client with a preconfigured contacts list linked to an AD server, the email client will write the email address for you.

So the probability of someone mistyping an email address inside the same company is, I'd say, low. Even lower if it's a recuring contact between two persons who know each others.

That's what's smelling here. You don't mispell an email address when you're replying or sending a message to someone you have an ongoing conversation with.

And if you receive that kind of email from outside the company... Well. That's phishing.