If you’re still using Yahoo Mail Basic version and have frequent connection timeout problems since mid-2013, then I recommend clicking on the upgrade link.
Full Featured version (free) does not appear to have those problems. The main drawback of this version is that Inbox paging was replaced with infinite scrolling.
Yahoos: something is misconfigured in handling Yahoo Mail Basic web browser requests …
It usually takes 3 Send requests to send an email after composing it, and often the same for refreshing Inbox. The browser status bar says, “Waiting for us-mg6.mail.yahoo.com…” for a long time on connection attempts.
Full Featured appears to work fine on the same computer (Macbook Pro Leopard, Firefox browser and Comcast Internet connection.
Oh, and please add a Settings option to disable infinite inbox scrolling. 🙂