You can access your Yahoo! Mail from another email client or your mobile device using IMAP.
Use these settings when configuring IMAP:
Incoming Server: imap.mail.yahoo.com
Outgoing Server: smtp.mail.yahoo.com
Incoming Port: 993 with SSL
Outgoing Port: 465 with SSL or port 587 with SSL/TLS
-It is necessary to enable SSL or TLS for Outgoing SMTP port.
Username: full email address (for example, free2rhyme@yahoo.com)
Password: the password you use to sign in to your Yahoo! Account
Since you cannot export directly from yahoo to providers like gmail you can enter this information into Microsoft Outlook to retrieve your e-mails to avoid agreeing to the new upgrade and still be able to retrieve your mail.
I was a Yahoo! customer for 18 years. Yahoo Classic is now gone. Yahoo's new service agreement allows them to scan all of your e-mail & I will not consent to that.