This is a question that came up during yesterday's training: "Does CiviCRM offer the feature of sending email change notices? If I go online and change my email address at my bank or broker, notice is sent both to my old and new emails. This gives not only a notice of change but also the chance for me to discover if I've entered the new email address incorrectly."
Any thoughts? If it's not possible now, would this be a good feature request?
Not out of the box, no. As far as a feature request - I think that this would be a good extension, but might not make sense in core CiviCRM - most CiviCRM installations don't even have uses where their contacts log in, let alone change their e-mail addresses.
To implement as an extension, a developer should use the hook_civicrm_pre hook on the Email entity - it's important to use "pre" and not "post" because otherwise the old e-mail address is already overwritten! Confirm that the change is driven by that person, not a back-end staff person (my comparing the logged-in user ID to the contact ID that owns the email), and if so, send a custom message to both addresses. I have an extension somewhere that lets you specify a CiviCRM template to send - the advantage being that a staff person can change the e-mail. Let me know if you need that posted on Github and I'll track it down.
