I am trying to change the email address connected to the account, and it won't let me save the new email address. What do I do?
Please clarify - how does it not let you save it? Does it show an error message? If so - what does the message say?
If you're using an email address that's already in use with Todoist, please log into the other account and change its address to free the email address which can then be reused on the other account.
If you're using the Google Login, you may need to deauthorize your Google Account in Settings -> Authorizations and then reauthorize it through a different Google Account.