An email sent as:

Hi!

Hello.

Bye!

when posted to a group list with the default Filtered HTML input format and sent from GMail in HTML mode becomes:

Hi!<br><br>Hello.<br><br>Bye!

and displays as:

Hi!Hello.Bye!

These tags should be intelligently filtered, but not in a way that would break mail should an input format that does not have automatic line breaks was enabled.

Robin