Customizing
Email subject
Control the subject line of the notification you receive.
By default every notification arrives as “New submission from <form name>”. That is fine with one form and unhelpful with ten — the subject is what you see in a crowded inbox, so it is worth setting.
Per submission
Send a subject field with the form and it wins for that message. Useful when one form serves several purposes and the page already knows which:
contact.html
<input type="hidden" name="subject" value="Enterprise enquiry">Per form
Set a default in the form settings instead, and every submission uses it unless the markup overrides it. Prefer this — a subject in the markup is one more thing to keep in sync across pages.
The subject is attacker-controlled if you let visitors fill it in. Keep it a hidden field with a value you chose, or set it in the dashboard.