It was a breeze for Mr Woo Keng Leong to remember all 28 postal districts here back in the 1980s when he was working for SingPost's predecessor. But this has since expanded to around 83 postal sectors and Mr Woo, 59, now head of SingPost's postal services, can no longer name all of them from memory.
He joined the Postal Services Department in 1980 and his responsibilities included planning delivery and collection routes for postmen.
"My history is very similar to SingPost's history. I started out as a civil servant. Those days, the key thing was to make sure that we provided good service to the public, now we are a listed company with many stakeholders," he said.
In 1982, two years after Mr Woo joined the civil service, the department became part of the Telecommunication Authority of Singapore, a statutory board.
SingPost was listed on Singapore Exchange in 2003.
ONE THAT STANDS OUT
I remember this stamp because it was launched when the airport opened in 1981. I still remember the area's four-digit postal code back then - 1781. It has changed now. Stamps are really like a history book.
MR WOO KENG LEONG, head of SingPost's postal services, on the stamp bearing the image of Changi Airport's control tower
With electronic mail more prevalent globally these days, SingPost's mail volume has been declining.
Mail made up nearly 60 per cent of SingPost's revenue for the financial year 2010 to 2011 but fell to about half for this and last year.
SingPost has been ramping up its business towards e-commerce and the online shopping boom. Last week, it said it had invested $75.6 million into expanding its e-commerce logistics and postal services.
Its revenue from logistics, which includes its e-commerce logistics business operations, rose by 43.6 per cent for the first quarter of the financial year 2015-2016 compared with the last financial year.
Postage stamps do not have a role to play in e-commerce, admits Mr Woo. "If I said there was synergy between stamps and e-commerce, I would be lying."
These days, stamps appeal more to collectors, said Mr Woo. Around 15,000 people collect local stamps and are mainly from Singapore.
In line with Singapore's Golden Jubilee celebrations, SingPost has released limited-edition stamps, including a sheet of 50 depicting designs from the past five decades.
Mr Woo himself is not a collector, but he is a member of the Stamp Advisory Committee, which advises the local authorities on philatelic matters such as appropriate themes and designs for stamps.
"When I first joined the Postal Services Department, the postmaster told me that I could not collect stamps because there would be a conflict of interest," said Mr Woo, who buys only collectors' edition stamps occasionally for keepsakes. Over the years, he has collected at least 100 of them. Stamps serve as a record of a nation's past, he added.
One which brings back memories for him depicts Changi Airport's control tower. It is part of the 50 designs depicted in the new limited edition sheet released last month.
"I remember this stamp because it was launched when the airport opened in 1981. I still remember the area's four-digit postal code back then - 1781. It has changed now. Stamps are really like a history book," he said.