Indication that something needs to be mailed...

(See Seal, Cauterize)...

A postage stamp put on a letter may point to the cost or value of the message sent or received in a dream. It may represent the payment of dues....

Literal, though timing may be elusive...

The amount may be symbolic, but it will be a true indication of value; research details...

(See Ring, Seal)...

Putting your stamp on something. Desiring a higher position....

It is a sign of remunerative activities to dream of collecting postage stamps as a hobby....

interpreted upon 5 sides: high rank, high standing, preservation / saving of something & collecting of wealth, blessing....