email ID

Is it possible (or easily possible) to tell if an email is being sent from the same location, but with different email accounts.

Yes you can check the "headers" or view the source of the email. You will see an IP address. From there you can find out the general location. They IP's will be the same if both emails are using the same ISP ( internet service providers )

the email headers will contain the ip address of the sender.. and possibly the sending email server.

If you have multiple systems on a single internet link (say, a starbucks, with half a dozen people on laptops) they will all "look like" the same address - the address of the starbucks. Same in a public library, or any other facility where multiple users "share" a single path to the internet.

You can identify "location" - but not "uniqueness".

Panama nailed it. IP addresses can appear on several email accounts if the private network is one used by many. (Starbucks, Library, cellular networks) it is no indication that the same computer sent the message. Like Panama said, "you can identify 'location' but not 'uniqueness'" At least not by any easy to use publically available method I am aware of.

I will only add that there are alot of 'it depends'. (see Tor for example).
There are email providers that will filter out your ip address, and/or replace it with another one.

I would like to point out that if someone is bound and determined to bug you in cyberspace they can do so without leaving a trail.. PM me if you would like to hear the details.