smtp.mail.yahoo.com (followed by ':587' if your ISP blocks port 25)
ESMTP | Login
Note that Yahoo! has a delivery limit of 500 messages per day and each message can be sent up to 100 recipients. You can also set security to SSL v3 or TLSv1 (pull down menu next to the SMTP host address field). In such case set the authentication to PLAIN rather than LOGIN (pull down menu next to Authentication).
As a precautionary measure to stop spam, many ISPs are no longer allowing outbound traffic on port 25. As a result, your ISP may have blocked port 25 on your account. Port 25 is the standard TCP port used to send e-mail via the SMTP protocol. Hopefully most SMTP servers offer their services through several ports. So, if MaxBulk Mailer can't connect to your server through default port 25 try to use port 587.
Important: Usually the Yahoo! SMTP server is deactivated by default until you verify your Yahoo! email address. You should also deactivate the two-step verification feature and 'allow apps that use less secure sign in' in 'Account Security'. If the 'LOGIN' authentication scheme gives problems try 'PLAIN' from the second pull-down menu next to 'Authentication'.
WAIT! In order to add a comment below just use your Facebook, Google+, Twitter or Disqus login data.