ই-মেইল ঠিকানায় @ চিহ্নটি কত সালে সর্বপ্রথম ব্যবহার করা হয়?

একটি ই-মেইল ঠিকানায় অবশ্যই থাকবে @ চিহ্নটি। ১৯৭২ সালে সর্বপ্রথম ই-মেইল ঠিকানায় @ চিহ্ন ব্যবহার করা হয়।
তবে, অপশনে ১৯৭১ থাকলে উত্তর ১৯৭১ সালে হবে।

From Ray Tomlinson himself -
"During the summer and autumn of 1971, I was part of a small group of programmers who were developing a time-sharing system called TENEX that ran on Digital PDP-10 computers............................Next, the CPYNET code was incorporated into SNDMSG. It remained to provide a way to distinguish local mail from network mail. I chose to append an at sign and the host name to the user's (login) name. I am frequently asked why I chose the at sign, but the at sign just makes sense. The purpose of the at sign (in English) was to indicate a unit price (for example, 10 items @ $1.95). I used the at sign to indicate that the user was "at" some other host rather than being local."
Also among many resources this one is from The Guardian.