When should I send a reminder email for recommendation letter? I am asking this professor about whether  he can write me a recommendation letter for PhD application.  I sent the email on Wednesday morning. Should I wait more or should I send him a reminder email now?
The problem is that he is my number one option and I spent almost all of my time during my master trying to get his attention. I think that if he rejects me I will not be able to find another person that can write me a letter. Hence I am just afraid that if I write a reminder email too soon there is a chance that he gets angry because this professor always takes like 2 weeks to answer an email (if he does answer at all)
Given the new understanding of the issue, I'd suggest that you write to him, apologizing for the mail, and with an explicit request to let you know if he will do this. Perhaps your first mail wasn't clear on that point.
But most professors receiving a request would normally assume that the default &quot;yes, I can do that&quot; is understood by the asker and only needs a reply if they won't or can't do it. I'll assume that is the case here if you haven't heard otherwise. But if you need this to be explicit, ask, but say you're sorry for the inconvenience.