After PhD interview Guide I had a PhD interview and the professor invite me over for a visit. We had a very nice day tour and I was supposed to send my idea about the PhD topic to the professor in two weeks and I did so.

Meanwhile they did reimburse the costs of my travel.

However, I didn't receive anything from the professor.

I was upset because even if I was rejected, the least he could do was a rejection email.

Now after almost 2 month I checked my email and I realized that I send him the topic discussion email via my gmail account instead of the uni one.

I was in contact with him with the uni account and once with gmail account before.

I still would prefer to get a rejection letter rather than no answer. 

What should I do? write him again? move on?
Unfortunately, academia is not always a model example when it comes to hiring practices. There are several reasons to it:


academics are often very busy. A senior faculty member can get hundred(s) emails in their inbox daily. The importance of these emails varies dramatically: most of them are general "academic spam", announcements, or something not really important. As such, most of the email is quickly trashed, including (sadly) potentially important emails from unknown address.
Academic positions are often very competitive. There can be hundred(s) of application for a single post, then reduced to a shortlist of 5 to 10 candidates. Sadly, not always HRs and academics have enough time (or motivation) to send a polite notice to unsuccessful candidates. Such a huge competition is mostly for faculty posts, rather than for PhD posts, but I imagine the attitude can be the same.
Formal procedures established by HRs can be very slow. Often academics can not make an offer of a post without HRs approval. Since HRs do not report to academic staff, a professor has a very limited possibility to speed them up. If some gears in HR department desperately need oiling, this can affect the whole university, but almost no-one except higher management can do anything about it.


There is one thing you definitely can try: email your professor again.

If this does not work, here is another one: telephone him (at work number in work hours).