Send email on invalid registration identifier

[macoca]

When a user want's to register to a chat campaign, he needs to call to a phone, thus changing mode, in order to get a registration identifier.

It would be great to setup a message in the bot to instruct the user to wait for the registration id to be generated, then send an email to an admin that can take over the bot and generate that id.

The cherry in the top would be not requiring the user to re-send the registration id to the bot to store it in his session.