Channel Express operated scheduled cargo/parcels services on behalf of various companies.
These I remember having been there.
Late 1980s - STN-BRU-STN 5 nights a week for Fedex. HPR7.
1990s - STN-EDI-STN 5 nights a week for Royal mail. After a while this changed to EDI-STN-EDI. L188.
Late 1990s/early 2000s - STN-CGN-EMA-STN 5 nights a week for UPS. A300.
Around 2000 - STN-LGG-STN 5 nights a week for TNT. A300. (G-CEXI in TNT colours)
They also started a scheduled weekly cargo service in their own right STN-IST-STN around 2002 with the A300, but I think it only operated twice.
There were also some F27 flights, but I was not involved with these.