Despite providing over 35-points of automaton when a new lead is ingested by Yabber from any source, the most effective notification for a broker is arguably via an RSS feed. As a new lead comes in the feed simply shows the lead, with the message providing all contact details (basic email-only leads aren't shown).
Other feeds exists for the standalone contact form plugin (no longer used on the standard broker website), SMS replies, and SMS delivery reports. Various order feeds are available, including one that'll show all marketing triggers firing off in real-time.
Pictired is a basic leads RSS feed in Outlook.