This is using Windows 2003 ad domain, with 2 exchange 2007 servers. Only one exch server - exch003 is join ad domain, holds 3 roles - CA, Mailbox, and hub transport. The other one is edge transport server - exch002. Recently, found that there is some delay for mail sending internally and externally. 3 major errors were found in application log in exch003 server:
Microsoft Exchange System attendant reported an error '0x80072020' when sending DS notificaiton.
2. Source: MsExchangeTransport
The remote internal transport certificate expired. Certificate subject: cn=exch002
3. Source: MsExchangeTransport
What's went wrong? How to solve it?