No not really unfortunately. Clients can choose to format messages any way they want to. Most email clients use HTML so any line breaks can be interpreted as explicit breaks in HTML.
The best way to ensure it works properly in most email clients is to forestall the plain text -> HTML conversion and send HTML. If you write out HTML all HTML clients will use that mostly as is.
If you are using plain text, I recommend making all line breaks CHR(13)'s only (rather than CRLF) which can also minimize space issues. FWIW, when I send plain text messages to Hotmail, they seem to turn out just fine.
++++ Rick ---