Hacker News Reader

You can just pipe your email through something that removes HTML.

Outlook seems to just ignore line breaks by default. But, there is probably a mime type to get around that.

HTML ignores line breaks. If you're using plain text, the format=flowed header is what ignores line breaks. Not all clients support it.

It's not just Outlook.

Exchange adds this mush to emails which were sent in plain text.