I would like to suggest OLM to Gmail Migration tool that deeply scans large size of OLM files to migrate all Emails, Mails data. This 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. I recommend you to first try its free demo version and analyze all features and working of this software.