How to fix error Error: CommunicationErrorTransientException:Could not establish trust relationship for the SSL/TLS secure channel with authority
we are running a ybrid environment , we create user mailboxes on our on prem exchange and than migrate the mailbox to exchange online , we have been doing that succesfully up until last week , when it started fsiling for all mailboxes , it stay for the whole day on sync and says completed with below error . the mailbox fails to migrate .
Error: CommunicationErrorTransientException: The call to 'https://owa.mtc.com.na/EWS/mrsproxy.svc' failed. Error details: Could not establish trust relationship for the SSL/TLS secure channel with authority 'owa.mtc.com.na'. --> The SSL connection could not be established, see inner exception. --> The remote certificate was rejected by the provided RemoteCertificateValidationCallback.. --> Could not establish trust relationship for the SSL/TLS secure channel with authority 'owa.mtc.com.na'. --> The SSL connection could not be established, see inner exception. --> The remote certificate was rejected by the provided RemoteCertificateValidationCallback.