I have received an email that begun with this:
My immediate thought was その後ってどの後, after which I proceeded to be further confused by the rest of the sentence. I'm guessing it means something like "How have you been (since I last sent you an email)", but the lack of a past tense throws me off.
What does this mean and what would be a polite response to it? And if it does refer to the past, why is there no past tense?