I'm sorry about the issue. Can you please click on the Apple logo / menu, then click on About this Mac, then tell me your Mac OS X version, i.e., 10.6, 10.7, 10.8, 10.9, 10.10, etc.?
Please try the following fix:
- In Safari application, click on the Safari menu at the top, then click on Empty cache if available, then Empty cache, and then click on Safari menu at the top again, then click on Reset Safari, and reset and check yahoo mail. If those options are not available, then click on Safari menu at the top, then click on option Clear History and Website Data..., and clear all cache / data, and check. If needed, click on History menu at the top, then Clear history, and clear, then check.
- If that does not work, please download and install the Firefox application at the website below:
, then quit Safari application
, then open Firefox application, then go to the yahoo.com website in Firefox application, then click on Mail, then sign in your yahoo email address and see if yahoo mail works fast in Firefox application.
Please reply at the box below to continue troubleshooting. Thank you.