The text in the title is what I was googling for today, finding nothing of value. So I include this post for others who might be looking for the same thing.
The answer is: “aroba” ie. persona (aroba) lared.es
Knowing this, led me to a page called A Natural History of the @ Sign where this information can be found for many different languages.
As an aside, it is fascinating to notice how the new computer and internet words are treated in different languages, from trying to translate everything (my favorite is the German “befehls-taste” for a function-key – it has a distinct stereotype prussian military kind of ring to it) to complete laissez-faire and adoption of all the English words, though sometimes pronounced in very much native dialect.
Is this a new thing? Hardly. The only thing that is new since the 1940’s, is that English is now the “lingua franca” – one Danish/Norwegian playwright put it like this in the 1700’s: “The Danes speak French with their wives, German to their servants, and Danish to their dogs”.