This is so trivially easy to bypass. If you're a service selling email addresses, just strip off the booking+ part and you have the "real" email address.
All my sign-up email addresses are via a catch-all email, so I can just give a service "thisservice@mydomain.com", or "thatservice@mydomain.com", so I there is no single "real" email address, and I get to track who exactly is selling my email address. So far I haven't had problems with anyone spamming "anything@mydomain.com".
They can bypass it, and as the user you can also use any other sign or character that you want. If you email is foo@ then you can use the letter x, as registrationxfoo@. A popular choice for a company email is first.lastname@, so you can use a . for it, or the - character. + is just what some program, like procmail and Sieve, will recognize without much trouble.
Using a a catch-all email with your own domain works also perfectly fine. Doesn't work as well if there is multiple email users of that domain.
This is so trivially easy to bypass. If you're a service selling email addresses, just strip off the booking+ part and you have the "real" email address.
All my sign-up email addresses are via a catch-all email, so I can just give a service "thisservice@mydomain.com", or "thatservice@mydomain.com", so I there is no single "real" email address, and I get to track who exactly is selling my email address. So far I haven't had problems with anyone spamming "anything@mydomain.com".