Some  more information would be fine

The job didn’t run. In application aware settings I enabled “perform copy only” since it is not SQL

I run a credentials test and it succeded.

Agent or VM Backup? How did you select the machine?

agent

We definitely need more information here. Let’s see some screenshots of the job configuration so we have a chance to provide useful feedback, otherwise we are just making some random guesses. Don’t forget, even with the free edition it is possible to open a support case and receive help there - they will need log files of course.

Exchange Cluster? DAG?

https://helpcenter.veeam.com/docs/backup/agents/dag_hiw.html?ver=110

Single machine

Dear @Anandu, could you please provide more information as already requested. Here is a similar error, I hope this helps: https://forums.veeam.com/servers-workstations-f49/veeam-v10-job-nothing-to-process-t66778.html 

Also try to ping the host from the backup server to see if it is reachable. If this is not an issue, try to rescan and if the issue still persists, check to see if the “single machine” is correctly added to the infrastructure.

Full machine backup? Single volume? What version of agent? What version of Windows? What version of Exchange? What CU and SU of that Exchange? And more… :)