I would like to suggest OLM to Gmail Migration tool that deeply scans large size of OLM files to migrate all Emails. This application maintains meta properties of email such as to, bcc, cc, subject, date, time etc. You can migrate particular data according to the date range using the Message Filtering option. At the time of conversion, it removes all duplicate email data.
lukewilson02
I would like to suggest OLM to Gmail Migration tool that deeply scans large size of OLM files to migrate all Emails. This application maintains meta properties of email such as to, bcc, cc, subject, date, time etc. You can migrate particular data according to the date range using the Message Filtering option. At the time of conversion, it removes all duplicate email data.