For me, the main benefit from aliases is that in the case of a spammer, it is easy to know who leaked the address. The "+" is an actual part of the standard and

For me, the main benefit from aliases is that in the case of a spammer, it is easy to know who leaked the address. The "+" is an actual part of the standard and it helps for self-organizing, but it is not useful against spam because it is okay to drop the +.* part (the mail will be delivered to the intended address).