Works

Automatically encodes email-addresses, just as it says. On the screen email addresses are openly shown to a human, while a bot cannot find an email-address there.
Address
In the source code instead of the email address in plain text, each letter is written with its HTML character entity (number). Looks just the same when the browser displays it.
Link
Also the link, which of course contains the email address, too, is encoded. By clicking on the link, it is decoded again, so the “mailto:”-link can be used as usual. For this javascript is used.
Accessible
Because the email address is also openly shown to humans as text (if it is inserted between the tags of course), even someone, who has no javascript enabled or just wants to copy the email-address, can find the email-address and use it.