“You are receiving this email because this is an important message regarding your account and products you are using. You are not allowed to unsubscribe from this type of message.”
Edit: To all the concern trolls who think the contents of the email is important context as to whether I’m allowed to be annoyed or not, understand that I am not Atlassian’s customer. We have zero active licenses for any Atlassian products.
Sounds like a reasonable email, and being able to unsubscribe from account-related communication would be a way of evading security measures to a malicious actor.