Import Mail from Thunderbird into Outlook - Version 4.1 How to Import Mail from Thunderbird into Outlook without losing access to the EML files? Import Mail from Thunderbird into Outlook using EML to PST Converter software which is developed by us. We launched this tool to help all those users who wish to Import Mail from Thunderbird into Outlook. Even after the EML files are converted into PST format, you do not lose access to them in EML format. Even after the conversion you can access your EML files into PST. EML to PST Converter easily converts EML files from Thunderbird database to MS Outlook with all email details such as – To, Cc, Bcc, Time and date, attachments, formatting, subject, etc. The program also saves the converted EML files into new PST file.