renluop,
This is using an add-on to firefox/chrome/IE which blocks trackers on webpages and also gives you the ability to use temp e-mail addresses that hide your real address. It can pop-up when your address is about to be entered into a form etc and substitute a temp address.
I use it in Firefox to 'kill' all trackers.
Seems to work and as far as I can tell does not get in the way of anything else.
Is a real company [Abine] that is trying to get you to upgrade from the free service by having paid added value extensions to cover credit cards and phone numbers.
I use the free service (6 months +) and it just works.
If used appropriately it is not overkill as it can be very useful to generate an email address that is not directly connected to you and can be deleted if you start getting junk/spam mail.
I know there are other methods including yahoo's disposable addresses but having options is always useful.
Having your real address & the opayq address in an email is pointless and creates a connection to your real address which is counterproductive.
Possibly let your friend know this is happening as it is not useful and he/she may be doing it unintentionally.