I would suggest you Mac OLM to Gmail Migrater tool which is very Effective software Transfer Outlook Mac to Windows. This OLM to Gmail Converter tool is an easy, reliable, fast, and secure tool to work. OLM to Gmail converter supports all MS Outlook versions such as 2019, 2016, 2013, 2010, 2007, 2003 and etc. This software supports batch conversion of multiple OLM files to Gmail at once.