EML is a file type for storing single email data or information. This file type is created by various email client such as MS Outlook Express, Zoho mail, Windows Live Mail etc. On the other hand OLM is a file type for storing mailing data such as multiple no. of emails, attachments, contacts etc. This file type is created by Outlook for Mac 2016, 2011, 2008 and older versions.

Now back to the query, if you want to convert .eml to .olm or combine eml files to olm format. Then I would simply request you to try Advik EML to OLM Converter. As there is no other official method to do so. 

The tool has been designed because of high demand for users who wants to import eml files into olm or Outlook for mac.

Steps to convert EML file to OLM with attachments;

1. Start and run the programe

2. Browse and add eml files.

3. Click convert.

Done! Nothing else can beat this solution. Your files will quickly converted to .olm file. After that you can easily import olm file into Outlook for Mac.