Emails with attached PDFs send as gibberish
When I send emails, I always BCC myself. Suddenly, every time I send a message with an attached PDF, it lands in my inbox as gibberish. I looked up this problem on Apple Community and saw a recommendation to disable everything in Privacy. That didn't fix it. I use Yahoo email but get to it through my email icon on my MacBook. Please help!
This is what I see at the top, then pages and pages of some kind of code. It shows up this way in my Inbox and in my Sent folder.
--Apple-Mail=_6802FBF0-8AFD-4459-B4D1-5EEFDC246BA1
Content-Type: multipart/mixed;
boundary="Apple-Mail=_45665629-7B5B-4BD4-AE41-C78692D93958"
--Apple-Mail=_45665629-7B5B-4BD4-AE41-C78692D93958
Content-Transfer-Encoding: 7bit
Content-Type: text/html;
charset=us-ascii
<html><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""></body></html>
--Apple-Mail=_45665629-7B5B-4BD4-AE41-C78692D93958
Content-Disposition: inline;
filename="2023 Buttons.pdf"
Content-Type: application/pdf;
name="2023 Buttons.pdf";
x-unix-mode=0644
Content-Transfer-Encoding: base64
MacBook Air 13″, macOS 12.6