You need to make a unique email for each service which will check. For example, there is domain for email "name.mail" and for each service is allocated the address "has service firstname.lastname@example.org". When a service sends a notification mail or something else then all the letters need to be transparent to come (without any logs, failed forward and let)... one email and if this e-mail reply which received the sender does not have lights hidden email and must be set to the intermediate e-mail.
At the moment the allocation of unique
email for each service is carried out through the extension addresses "name+(of the private key . service name) as email@example.com". But when you reply to this approach ukazyvaetsya clean email without the extended address that is not the hood and this email does not pass validation in some services, which is strange since this is the Internet standard.