Because exchange 2007 isnt really compatible with outlook 2016 autodiscover we want to use POP and SMTP on this server. But the current receive connector rules only allow specific IP addresses.
Also because they have on site scan to email printers we have had to allow the permission groups such as anonymous,
Because of this i cant see how i can allow all external IP addresses without opening up a big hole for spammers to abuse the server.
Has anyone got any suggestions how i can allow local scan to email with anonymous user but only allow external IP users to email with credentials?