Thanks, @jmon, it's interesting.
Although I'm using mailx via local ssmtp at my Arch Linux workstations (both at work and at home) for this - didn't notice such issues.
I'm not at all an expert in that matter, and won't investigate further. It can probably help others in my situation.
However if you're interested, I can provide you some configuration information if you guide me a bit.
Anyway thank you for your very nice work!
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