Subservient/Servile Written Malay
The differing tone of formal written English and Malay.
Formal and well-written English tends to be assertive, and imperative.
Contrastingly, formal and well-written Malay tends to be subservient in tenor, and almost servile (for lack of a better word).
Case in point: your letters. It'll be strewn with:
"...saya dengan rendah dirinya"
"...saya dengan segala hormatnya"
"...saya mengambil kesempatan ini untuk merakamkan setinggi-tinggi penghargaan"
"...kami mengucapkan ribuan terima kasih"
The above? It feels and reads quite like the linguistic forms of the Japanese registers for respect-granting/self-deprecation: 尊敬語 / 謙譲語.
For native speakers of English, ultra-courteous Malay can come off as gratuitous grovelling. I of course disagree, but I find this cultural difference rather fascinating.