The @ Symbol
The symbol's history is a bit cloudy. This is what we know.
Before its use on the internet for e-mail addresses and use handles, the symbol was used to mean a rate. ie: I purchased 3kg of beef @ $2/kg. Before that, one of the first uses was as a symbol for the arroba in Spain and Portugal. It was a unit of weight of about 12kg.
It’s not like the ampersand, where it says and but has the name ampersand. The @ symbol is pronounced at and is called at.