"
Yeah, this "1024 × 1000" style shows up a lot in older storage/networking contexts. It looks weird today because we're more strict about MiB vs MB, but historically vendors mixed binary and decimal units all the time depending on what felt convenient or marketable.
In this specific case, 51200000 is basically "50 MB" in the old hybrid interpretation:
50 × 1024 × 1000 stickman hook
So it's not really mathematically clean, just historically inherited behavior. Postfix probably kept the convention because changing it later would silently alter existing size limits and break expectations/config compatibility.
Also worth noting: mail systems traditionally cared more about approximate operational limits than exact IEC correctness, so "close enough to 50 MB" was likely considered perfectly acceptable at the time.
In this specific case, 51200000 is basically "50 MB" in the old hybrid interpretation:
50 × 1024 × 1000 stickman hook
So it's not really mathematically clean, just historically inherited behavior. Postfix probably kept the convention because changing it later would silently alter existing size limits and break expectations/config compatibility.
Also worth noting: mail systems traditionally cared more about approximate operational limits than exact IEC correctness, so "close enough to 50 MB" was likely considered perfectly acceptable at the time.
