You can easily migrate Mac OLM to Gmail using professional software like KDETools OLM to Gmail Migration Tool. The software easily migrates OLM to Gmail, G Suite, Google Drive and etc. The software also migrates OLM to different file formats such as PST, MBOX, EML, EMLX, HTML, PDF, NSF and etc. The application allows the user to migrate the oversized OLM files to Gmail without any data loss.