Those unused to English fake 'politeness' might find these translations helpful.
That’s not quite what I had in mind = What the bloody hell is THAT?
Maybe I haven’t explained this very well = A toddler could understand this; I can’t believe I have to deal with someone so dim-witted.
Just checking in = I am going to continue to send you emails about this until you either respond or get the job done.
No problem, whenever you’re ready = Glaciers move faster than the pace at which you do things.
I may be wrong, but… = I know I’m right and I’m about to tell you why in excruciating detail.
As per my last email/as discussed = I can’t believe I am having to repeat myself, can’t you read?
With respect/all due respect… = I think you are a fool and am about to say something severely insulting, but I’ll be nice and soften it with this classic bit of British pseudo-politeness.
I see your point, but… = I listened to your argument out of politeness but you are obviously clueless so I’ve just been waiting for you to finish speaking before I demolish you with my superior knowledge.
That’s one way of looking at it = By which chain of mangled reasoning did you arrive at that conclusion?
I’ll bear it in mind = I’m going to erase it from my memory as soon as you stop speaking.
How interesting! = This is 100% the opposite of interesting. Please stop before I pass out from boredom.
I’m not keen on it = I can’t think of anything worse.
How are you? = I’m not even remotely interested in how you are doing, it’s just a formality. Please just say “Not bad, thanks” like a normal person and we can all proceed with minimal awkwardness.
Not bad, thanks = Could mean “I’m feeling OK, neither great nor bad” or “I’m just saying anything to get this bit of the conversation over with” (see above). Or, it could mean “I’m on top of the world, just won the lottery and got a new girlfriend who is an Oxford graduate who does modelling on the side, but I’m not going to rub your nose in it, peasant”.
I’m not feeling too chipper = Call an ambulance.
I’ve been better = My life has crumbled about my ears.
I’m a bit under the weather = I feel like death warmed up.
I’m in a spot of bother = The police, the bailiffs and my psycho ex-wife are after me, I’ve been kidnapped by terrorists and the boat they are taking me away on just capsized on the open sea.
We’ve never seen eye to eye = He/she is quite simply the worst person I have ever met.
She’s lovely really = She’s terminally dreadful and I’d rather stick pins under my fingernails than spend more than 10 minutes in her company.
That’s quite a striking outfit = You look like you covered yourself in glue and ran through a thrift shop.
You must come over to our place sometime = You will never see the inside of my house.
I might pop by later = I’m not coming.
We should hang out sometime = You will never see me again.
Don’t let me keep you = Please leave.
Well, I’ll let you go = Please leave, NOW.
Well, I’d better start making a move then = I don’t want to be here anymore, but I suspect I’ll be trying to leave for at least another hour.
(Apologies, by the way - I can't remember where I first saw these translations. I would be delighted to credit the author if they reveal themselves.)