I'm updating on myself. Is this a bug in the Ajax interface? The html interface interprets correctly the line breaks "%0A%0A"
examples: (replace FQDN by your own address)
Ajax:
https://FQDN.com/?view=compose&to=ac...aragraph%0A%0A
HTML:
https://FQDN.com/h/search?action=com...aragraph%0A%0A
Should I submit a bug report?