Exchange Server 2016 DAG question

Hi All,

Have some questions about Exchange Server 2016 that need your help.

Our company has 3 sites connected by dedicated lines:

Site A:

There are 3 Exchange servers

Site B:

There are 2 Exchange servers - SJMAIL1 and SJMAIL2

IP range : 172.16.26.x

Site C:

There are 2 Exchange servers - FCSMAIL1 and FCSMAIL2

IP range : 172.16.51.x

DAG - CCGMail contains Exchange servers (4 servers) in Site B and Site C. 

The witness server SJPDC is on site C,

Last week, the dedicated line between site B and site C disconnected, mail client on site C can access their Exchange server, but all mail clients on site B cannot access Exchange servers until the  dedicated line re-connect.

I plan to add a new Exchange Servers SJMAIL3 on site B. Total DAG member will be 5 Exchange servers. 

Question 1 : If the dedicated line between site B and site C disconnected, mail clients can access the Exchange servers on site C. Can mail client on site B still access Exchange Servers ?

Question 2 : If mail clients on site B still access Exchange Servers, what Exchange and mail clients will happen when the  dedicated line re-connect?

Best Regards,

Borland