CommandBox on Windows here with the latest Java 8 and whitespace management off. But turning it on makes no difference.
To isolate this within Lucee, try running my test, but using a non-existent mail server so that sending fails. The generated mail should be saved into the equivalent of ACF’s “spool” folder, which is
WEB-INF/remote-client/open. Open the “.tsk” file with a text editor and search for “Line1”. Have the CRLFs been added or not? This is what I’m seeing:
...localhostpppt t Line1
Line3sq ~ =w UTF-8...etc
You can see that the line breaks are there.