Praise be to Allah.
We ask Allah to enable us and you to do good deeds and to grant us a good end, and to make our abode Paradise by His mercy.
Collecting stamps is subject to further discussion:
if it is done by way of a hobby, then it is permissible to collect them and keep them on condition that they are free of anything that is contrary to Islamic teachings, such as haraam images, images of crosses, Jewish and Christian symbols, and other symbols of kufr (disbelief).
If they are free of these shar‘i reservations and you do not waste a lot of time with them, then it does not seem to us that there is anything wrong with that, in sha Allah.
The scholars of the (Standing) Committee were asked:
With regard to the hobby of stamp collecting, please note that some of the stamps carry images of humans and animals. Is it permissible for one who owns the stamps to sell them, whether they contain images or not, so as to make use of the price to buy Islamic books?
The committee replied:
It is permissible if they do not contain any images, and it is not allowed if they do contain images. End quote.
Fataawa al-Lajnah ad-Daa’imah (26/299)
If collecting is done by way of buying and selling, then this is not permissible because it involves wasting money on something that is of no real legitimate benefit. In addition to that, they are usually very expensive and overpriced, to such an extent that the matter goes beyond buying and selling to the level of foolishness and extravagance. The Prophet (blessings and peace of Allah be upon him) said:
“Allah hates three things for you: spreading gossip, wasting money, and asking too many questions.”
And Allah knows best.