There must be more to life than this
Peyton wrote : "To most of us, it's discourteous, impolite, and unprofessional. Does that make better sense?"
No. Do people not exercise their judgement anymore? Has email rendered us incapable of 'reading between the lines' and appreciating variety, human expression and personality, or even finer subtlety and nuance? Does everything become black and white the moment it's committed to an electronic format?
If I'm turning a funny shade of purple and your ears are bleeding, it's a fair bet I'm shouting (rather aggressively) at you. If I'm simply talking to you these side effects won't be in evidence.
Are there no shades in between?
Do we get on the internet and think "lower case - reasonable, upper case - mad shouty bastard"? Just because it's supposed to be 'convention' that upper case characters are 'shouting', is there still not room for applying a little common sense and thinking for ourselves?
It reads to me like the lady in question was merely trying to emphasise the importance of something - not being rude, impolite, or offensive. Like I said, if I was an employer I would be seriously questioning the judgement, maturity and emotional stability of those who got their knickers in an etwist over a few capitals in an email.
But, as has been mentioned, I suspect there's more to this than just a case of misguided capitalisation.