Issue Summary

It seems like quite an edge case, but - the email address in the `Email-to-board` feature is always available, even in case the Board does not have any list created. That lead to email sent on a board email address does not create any card on that Board, and user just receives email reply specifying the issue - inability to add a card as there is no list on a board. 

The time frame between "get board email" -> "send email to board" -> "get reply with error" -> "make changes on Trello board" could be quite long. And even worse, as a user could have no access to Trello at the moment I try to sent email to my board and get those error notifications.

Wonder if instead of reply on email with error, we could just show it blank / hide the `board email address` field, unless at least one List exists on a board (in case we do not specify the List in the Email-to-board feature, it just gets the first List from the Board and create card there, with corresponding comment in the email reply). This will decrease the timeframe between the wrong feature setup and user facing error in a result dramatically.

Steps to Reproduce

1. As a Trello user create a new Board with no lists created yet
2. Go to the Board Setting -> Email-to-board modal

Expected Results

• The email address is either blank or hidden unless there is at least one List on a Board
• Error / Info message in the modal describing necessity to have at least one List on a Board for enabling the email address

Actual Results

The email address is available and user could send email to that address which leads to no card is created on a board and reply in email clarifying necessity to create a list on a board

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available