Choosing a backup provider you should consider it performs incremental backups of Exchange Online accounts or individual mailboxes. As well a very important thing is a pricing model, scalability & flexibility, and outstanding 24/7 support.
Keep in mind that with offline backups of your Exchange Online mailboxes and emails, your data is safe from cybersecurity threats. With third-party backup software, you can schedule Microsoft Office 365 backup jobs to run automatically based on your data protection policy instead of running them ad hoc.