To ease the load on the server during an anti-virus scan, you can configure scan exclusions by limiting the range of objects to scan. Anti-virus scan exclusions apply to both e-mail traffic scanning and background scanning of storages.
You can configure anti-virus scan exclusions as follows:
Files with names matching the specified masks are excluded from the anti-virus scan.
Messages addressed to the specified recipients are excluded from the anti-virus scan.
If the application is running on a DAG of Microsoft Exchange servers, all exclusions from scan configured on any of the servers are automatically applied to all Microsoft Exchange servers in the same DAG. Configuring exclusions from scan on the rest of the servers in this DAG is not necessary.