Current configuration : multiple hub transport servers, multiple CAS servers, third party messaging gateway
Dirsync is already in place for other functions
wildcard certificate exists
i didn't yet completed or tried HCW
1. after HCW mail flow for on-premise users will stay the same ?
2. do we need to publish all hub transport servers to internet/port 25 ?
3. what IP adreses does hub transport communicates with, what ip addreseses i need in firewall rule , these https://technet.microsoft.com/en-us/library/dn163583%28v=exchg.150%29.aspx
4. i was thinking first leave MX record as is pointing to SMTP messaging appliance and after we are clear that everything is ok , point it to EOP ?