I have the current 7.5 running and created an internal and an external domain, the internal domain is also necessary because of the AD. Is there a possibility to change the primary domain to postfix, so that the SMTP header doesn’t contain a local address anymore? Apparently this leads some recipients to problems with graylisting and spam detection, which is actually nonsense, after my check there are many private IPs or something else in it, and even a headercheck does not cause big problems up to the local address. I send via Provider and Smarthost.
Which solution would you recommend to minimize problems?