[woranl]

There is nothing before the first @, and nothing after the last @.

[ojame]

While that's true, `@@.@` fulfils "an @ symbol with something before it, and something after it".

[Skadabucci]

The original comment probably meant something like this: ^[^@]@[^@]$

[mekster]

That's only one letter before and after.