I have established a group in my list of addressees. When I open the email composition dialog by clicking on write and select the group from the address list, then compose the message and click send, I get an error message telling me the address, which is the group name, is not a valid address. This just started happening about a week ago. Up to then, this worked fine. The work around for the moment is first to open the group, from that dialog select "write", then compose the message and select send. This is a bit awkward, since I often want to send my message to more people than just the ones in the group.