Mr. AJA Oudenampsen
When studying older postal items, the names of addressees or the addresses themselves sometimes stand out. Then you become curious: who was that addressee? What can we find out about him or her? This is also the case with the name appearing on a Jubilee Envelope issued on the occasion of the 50th jubilee of HM Queen Wilhelmina's reign.
On this envelope are several Wilhelmina stamps, designed by Sem Hartz, and an impression of a 'First Day of Issue' stamp dated August 31, 1948. The letter was sent as registered mail from Batavia on September 3, 1948, and arrived in Epe on September 8, 1948. The address: Huize “Yselnoord” in Epe, Gelderland, suggests that this concerns a retirement home. A further address is missing.
The internet can provide a solution. House “Yselnoord” cannot be found. So this building probably no longer exists. However, the name Oudenampsen occurs quite frequently in Gelderland and the surrounding area. But the addition of the initials AJA yields the following results: …On February 25, 1921, we read in *Het Vaderland* and on February 26 in the *NRC*:
First Lieutenant AJA Oudenampsen of the 7th Infantry Regiment has been assigned to the Volunteer Home Guard, Vessel Service Section, in Amsterdam.
and on April 14, 1921:
1st Lieutenant AJA Oudenampsen, of the 7th Infantry Regiment in Amsterdam, is being transferred to the 22nd Infantry Regiment in Ede.
and on March 7, 1928 in the NRC:
First Lieutenant AJA Oudenampsen, of the 22nd Infantry Regiment, is seconded to the Volunteer Home Guard in the Ruurlo Home Guard unit, stationed in Enschede.
Further: Arnold Johan Albert Oudenampsen married to Carolina Alberta Bourgonje…
Could this be the same person? Had he retired to “Yselnoord” House in Epe after his military career? Perhaps we will never know! The building apparently no longer exists or has been given a different name. It is a good thing the internet exists, though. There is so much information to be found. Unfortunately, not always a complete answer, so continuing to search for solutions always becomes archival work. That makes collecting old postal items quite fun, too! 
In my family tree records, the person in question is known under number K.90.
Arnold Johan Albert Oudenampsen, born in 1891 and died in 1963.
He was married to CABourgonje.
I have more details, but I do know that his son Jan died in Epe in 1948.
According to my family tree records, this is Arnold Johan Albert Oudenampsen, born in 1891 and deceased in 1963. He was married to Carolina Alberta Bourgonje.
His son Jan, born in 1930 and died in 1948.
Searching for mail recipients is great fun. I do it often myself. While searching for Professor Holloway, I came across the following Australian site: http://www.auspostalhistory.com
There are many examples there. They even have a name for it: Social Philately.
I was also curious whether the building still existed and what its function would be (or have been). I thought perhaps it was a typo; Ys(s)eloord or IJs(s)eloord seems more likely. But based on that, you only find the business park of the same name in Arnhem on Google. I emailed the local historical society because I wouldn't rest until… The building turns out to still exist, but it is no longer called that. It is a detached villa, located at Heerderweg 38 in Epe. The house was sold very recently. See http://epe.www.miljoenhuizen.nl/details/propnl/635352/Heerderweg-38-Epe . Elsewhere on the internet, I read that the building supposedly dates from 1938, so in 1948 it had only been standing there for 10 years.