emails wont download on windows mail app
Recently I have had constant issues with yahoo mail on the Windows Mail app including emails not downloading and many of those that do download rendering incorrectly.
The ones unable to download are only a few KB in size, so it's hard to justify that after several hours of the email arriving it is still not downloaded and refuses to download if attempted manually.
The emails with rendering issue will either show as either raw header data or raw HTML code, these are frustratingly hard to parse in the case of the HTML code, and completely useless in the case of the raw header data without any of the message body. Coincidentally some of these emails are also sent to other emails accounts that render fine in the Windows mail app.

Hi there,
Could you please message us on Twitter at @YahooCare or on Facebook at Yahoo Customer Care? We'd like to look more into the issue you're experiencing. In case you do not have a social media account, we are also available at: help.yahoo.com
Looking forward to your reply!
Thank you,
Yahoo team