Stansted Airport is also classed as a London Airport and served well by the Peterborough area as it is north of London and travelling time is shorter than Heathrow Airport and Gatwick Airport.
Stansted Airport is accessed from Peterborough via the M11 which does get very busy an peak times.
You can find out which flights go into which Stansted Airport by looking on the Stansted Airport website. Heathrow Airport has business lounges that can be booked for meetings with colleagues or to relax in before your flight.
Enroute Stansted Airport taxi staff can advise on pick up times for outward journeys.