Veeam Backup & Replication Version 10 supports the ability to use the following Amazon. Just realize that REFS is slower so you may need faster disk underneath if your incremental is big. Supported Amazon S3 storage classes and best practices. Use REFS on Windows 2016 for your backup target file system, self healing, no checkdisk, limits that you probably will never approach for file or volume size.If you need to go farther than that add in synthetic fulls to cut down on your merge time Forever Incremental is a great space saver and works just fine for about 6 weeks of daily backups.If you are running a backup copy job don’t do it more than once a week.Do not run Health-checks or Compacts more than once a month.Turn on Indexing on the Job for faster restores through Enterprise Manager.

Use Local Administrator account for AAIP, don’t use domain credentials.A slow proxy can increase the sync time which is required to check for changes on an M365 object during an incremental backup run up to several minutes. Make sure guest interaction proxy is on same network as exchange servers Any kind of proxy or traffic shaping in the connection between the VB365 proxies and the M365 API servers can badly influence performance.Increase timeouts for Exchange Failover.Do Not use VMXnet3 use E1000E for all adapters.This is just a list of things I have that seems to get Veeam and Exchange to a point of set it and forget it.