Searching hasn't found me a case quite like I've run into.

My N9 somehow has started to fail to get attachments in emails from one particular sender. Every week, she sends a newsletter in pdf format. I get the email body, but the attachment is missing. My wife gets the same email, but she gets the attachment intact. If she forwards me the email she received, the attachment is there.

I get another pdf weekly newsletter from another sender using the same domain, same email system. Those attachments appear for me just fine. I get attachments sent by everyone else -- as far as I know.

When I get home and download my emails on my PC, I get the missing attachment (in KMail, no less). I can even forward that email back to myself (same account) and then see the attachment on my phone in Fenix. Wrong, wrong, I can't forward it to me.

The incoming mail is plain old POP3.

Anyone got an idea? Obviously, it's work-aroundable, but I'd really like to know what gives.