An error occurred while saving the commentsteve smith commented
You can do manually importing single pst file to office365. But you can’t import multiple pst files manually. So, to overcome from this problem you have to use tools. In these tools you can perform many functions like import bulk pst files, recover pst files and many more.
I suggest you to use PST Converter. If you are not aware with the working of software, then start with free demo.