To export POP3 emails from Mailbird we have created a special tool. The tool can export to a .eml format ot to an IMAP server of your choosing. You can access the tool from this link
After you download it simply extract the zip and run "MailbirdBackupTool.exe". Follow the instruction given and your email should all be exported. You can also see the picture below for further instuction
Choose the POP3 account that you wish to export on this window. Don't forget to choose whether to upload to a server or export as .eml
Enter your email server detail if you upload to an email server and press next, if not see step 3
Browse the location where you want to save the .eml and press next
Wait until all emails are exported and you are done.
We recommend exporting to .eml since it's faster. Note that the operation is per account, so you need to start the wizard for each account. And please back up your Mailbird database file first before you export. Your Mailbird database file can be found in here
'C:\Users(UserName)\AppData\Local\Mailbird\'. Replace (UserName) with your Windows user's name - e.g. John Doe
Contact support at email@example.com if you are having issue with the export tools.