Is it possible to trace where an item of post has been sent from?

This morning I received a franked envelope which was empty. The franking mark does have what looks like a dedicated reference number and I tried the Royal Mail website but think you have to be a member of MENSA to find an answer on it!

The franking mark has two numbers aside from the postage itself. One is the unique reference of the machine which printed the franking amount, the other is a randomly generated unique number for that transaction.
Does the franking mark have Pitney Bowes or some other company's name on it? It should do. Then you can Google it and contact the franking machine issuer and ask them for help. It's the machine reference number plus the "Town Circle" you need to give them - e.g. sent from Harrow, London W1 - this is on the frank as well.

It's a long shot, I know, as no doubt they will claim data protection bollox or something, but still worth a try.

it is actually stampe on the envelope

yes if u posted it lol