Linebreaks not displayed

[gasell]

For some reason \r\n linebreaks in my mail message won't be displayed. They are there when I view the source in Thunderbird but not Thunderbird nor Gmail displays them. What could cause it?

[RonPK]

What is the content-type of the message? Text or HTML?

[gasell]

But of course, I had text/html. Changed to text/plain :).