Hmm, I can't reproduce this in Opera or Chrome. In
opera://settings/addresses, I have 3 entries each with their own email address. None of them are suggested in the email field on the site. Same with https://www.join.me/login.aspx.
In that settings location I have 6 physical addresses 3 of which have email addresses none of which are the ones that show up in 6 email addresses that show up when I click in the email field at join.me!