Is it appropriate if my current affiliation is different from the ending of my email address? I have a permanent email aliasing from my previous institute. My current academic affiliation (let's pretend it is Horvord University) does NOT give me a permanent email address. 

Now, I am going to submit a paper to a journal and I wonder if it is considered professionally appropriate if I list Horvord as my affiliation but list my previous email as the contact?
Yes, I think it is true to some degree.  I received such an email before and it made me wonder what is going on.

Although it is not really prohibited and people understand that situations cannot be generalized, it gives a strange feeling to some people at least.

It is like indentation and font size in a paper submission.