Has anyone used Azure for backing up PST archives?

[Kushina]

One of my users, CEO, gets about 4-8gb of email every 3 months not counting spam and she often needs to go back into her emails. Even as far back as a year or two.

I'm looking at Microsoft Azure since it's better at backing up PSTs but my question is will the entire PST be backed up again if she moves a few emails into and out of the archive?

Also I'm looking for suggestions on how to handle her backups.

 

[Elixer]

Give this a read, it will answer most of your questions.
https://azure.microsoft.com/en-us/blog/cloud-backup-of-pst-files/

For reliable tracking of block level changes, Microsoft Azure Backup products use either a kernel mode component called File System Filter Driver or maintain checksums for changed blocks on a file. Both approaches use OS documented features and APIs to intercept file I/O without blocking applications associated with the file, to store the information about only the changes on any file (such as PST) in a volume

You looking for hard backups, or multiple clouds to backup stuff?