In the second Set Up an Existing Email Account dialog:
Select the radio button for the desired server type, in this case: POP3 (keep mail on your computer).
Click the Manual config button.
In the third Mail Account Setup window enter the following information:
Incoming:
Server type - POP3
Server hostname - pop.bizmail.yahoo.com
Port - 995
SSL - SSL/TLS
Authentication - Normal password
Username - Enter your entire main business email address.
Outgoing:
Server type - SMTP (default setting, not editable)
Server hostname - smtp.bizmail.yahoo.com
Port - 465
SSL - SSL/TLS
Authentication - Normal password
Username - Enter your entire main business email address.
Click the Done button
Control deletion of messages from the server
Click the hamburger menu, mouse over Preferences, then select Account Settings.
Click Server Settings under the appropriate mail account on the left.
Use checkboxes to specify your preferences.
Leave messages on server (if you don't want messages to be deleted from the servers when they are downloaded to Thunderbird).
For at most ___ days (if you want to specify how long copies of downloaded messages remain on the servers before being deleted from the servers).
Until I delete them (if you want copies of downloaded messages to remain on the servers until you actively delete them or the Business mail account is closed).
