Customer want to use their own wblock spam server with exchange 2019 hybrid server to secure their onprem user mailboxes. I am not sure is it ok to communicate with between exchange 2019 hybrid and M365 Exchange online using MRSProxy protocol when we do mail migration to EXO on blocking wblock.
Do I request to open in/out bound port as 80, 443 going through wblock without blocking mail migration? Please give tips to me. This is first time exchange hybrid migration with other spam server, I am confused of it.