Quite often, questions like this recent one are posted, all with the same tenor:
I was in contact with a professor/supervisor/etc. about a position/PhD program/masters program/etc. , and they seemed to think I am a good fit. After initial contact I sent them a follow up email to which they did not reply (yet). It has been XX days since I wrote the email (sometimes as little as 3 days if I remember correctly), should I write a follow up email/call/etc.?"
I think there must have been 10 or so questions like this within the last few months.
So the question is: as this seems to be a common issue, should we make a canonical question about the etiquette and strategies when waiting for an answer? Or is this problem to profane for that and we simply keep on linking them to the oldest such question and close as duplicates?