How should I respond to "no research position available" from a cold email? Yesterday, I sent a &quot;cold&quot; e-mail (i.e., an unsolicited email to someone I do not know) to inquire about whether a professor has open research positions. Today I got the reply as shown below. Obviously, it is not positive.

Thank you for your interest in my lab – unfortunately while your skill set looks to be ideal for the lab – I currently do not have any positions available.

The answer is not very surprising. But how should I respond positively? Because we are in the same city, and probably one day I would have a chance to work in that lab.
There’s no need to respond.

An (uninvited) question has been asked and (kindly) answered. Answering required the professor’s time. There’s no need to follow up, because that will require more of the professor’s time. 




  Obviously, [the answer] is not positive.


I don’t know whether you mean “the professor answered that the lab has no open research positions” or the professor does not see you as a promising candidate or similar. Regarding the latter, you should not be concerned. The professor probably receives many such requests and simply doesn’t have the time to provide lengthy replies. (That’s why I recommend not to respond.) 




  Why would a professor waste their time with evaluating the suitability of a candidate if there are no positions available


The professor might not have even read the email, let alone evaluated the suitability of the candidate. Indeed, the professor might be using canned responses, which can be sent almost as quickly as an email can be deleted/archived and are perhaps better than non-responses.