Online form: allow form submitters to control whether they get an email #1563
Description
Currently, the shelter can choose whether an online form submitter receives an email containing a message and/or a copy of the form submission.
One customer recently had a from submitter who claims to be an IT professional, moaning about PII being sent by email.
Allow a special form field of type checkbox with the name "emailconfirmation" to be included that allows the form submitter to opt-in to receiving a confirmation message.
If the field is not present, we use the options on the form as normal. Some people might want it ticked by default. The simplest way would be by including emailconfirmation=on in the URL.