Before you proceed, make sure that both email accounts are added in Thunderbird. If not, please refer to our email setup with Thunderbird article (we recommend for you to use IMAP so that all incoming emails are synchronized to the server and not downloaded in the email client). If you’re ready to proceed, then you please follow the instructions below on how to transfer emails using Thunderbird:
Transfer emails using Thunderbird Email Client
This is applicable to all email accounts that are added in Thunderbird.
Step 1. Open Thunderbird.
Step 2. Select the email account.
Step 3. Open the folder where the emails are stored.
Step 4. From the menu option, click the arrow next to Edit and choose Select All.
Step 5. Right click on any message. Select Copy To, choose the email account and the folder where the emails will be copied . (Click the image to zoom.)
Step 6. Wait for Thunderbird to finish the copying of emails.
Step 7. Check if all emails are copied successfully.
If you have further questions, please do not hesitate to contact our support team.