[bendtherules]

How about telling them to reply something like "ok" to the email just sent on login request. That email should properly have this instruction written so that someone can copy paste that code word if required.

Also, the email can have pre-built email link with the text and aprropiate sender written so that one just click it and send.

[bendtherules]

Infact, this distinction of login system from the account itself can help in interesting consequences.

Consider like a command-line app running (actual stuff you do after login) along with a separate command center (your email), so that you could do queries about your account like who are logged in, logout everyone, or are there any pending notifications, and even is the service properly running?

But yes, people today dont like to do anything other than clicking buttons, so only geeks would be impressed with this.