Steps to add iCloud Emails to Mozilla Thunderbird :
Step 1: Now, go to the email source list and choose iCloud. Here, enter the details of your iCloud account such as Email address and password. Then, hit on the login button to begin.
Step 2: Thereafter, preview the entire iCloud+ data and enable the specific email folders which you want to import from iCloud+ to Mozilla Thunderbird.
Step3: Then, navigate your mouse towards the saving options list and thereafter, choose Thunderbird.
Step 4: Now, use the Advance settings option for selective backup if required.
Step 5: Then, hit on the backup button to start to add iCloud to Thunderbird.
Thus in this way, one can add iCloud emails to Thunderbird. Now, open your Thunderbird account to check the migrated emails.