We’ve made the difficult decision to discontinue the Yahoo Communities effective Jan 24, 2019.
Be assured you will still be able to find answers to your Yahoo product and app questions on the Yahoo Help website (https://help.yahoo.com). In addition, you’ll be able to find the Yahoo Community moderators on Twitter, responding from our many handles including @YahooCare and @YahooFantasyCC.
If you ever need help with your Yahoo accounts, try Yahoo Account Pro for 24/7 live phone support.
If you open up the email in the Sent folder, do you not see the attachments? If needed, take a look at the browser troubleshooting steps in this post to see if that fixes the issue.
Clearing the cache shouldn't have affected the attachments. If you open the email, can you see the attachments? What if you save them and forward them attached to a new message?