If you type in the name of a contact, you get the drop-down list of
matching contacts, from which one would ideally chose one. Then the contact
name becomes underlined; if the message is sent, the associated email
address is used.  However, if you don't select a contact from the drop-down
list and click send, Evolution will not complain that it doesn't have an
email address. If there's only one contact that's not underlined at the
time the message is sent, the server will complain, if there are other
valid email addresses, however, it will not. Then the message will not be
sent to all intended addressees. This is especially annoying if you
cut-and-paste conatct names from, e.g., the CC line to the To line: then,
Evolution will not give you the drop-downs, will not complain about not
knowing which email addresses to use, and will silently lose the intended
recipients from the outgoing message.

Steps to reproduce the problem:
1. New message
2. Type name of contact, but don't select from the matching contacts list
3. Click send

Actual Results:
Mail is delivered to SMTP server with empty To: line; SMTP server will
complain with a "DATA response error". The message is left in the outbox.

Another scenario:

1. Pick a message sent to a number of people, all of whom are in your
contact list.
2. Hit Reply All: the sender contact will be in the To line, everyone else
in the CC: line.
3. Select the CC line, Ctrl-X, click in To: line, type ', ' then Ctrl-V
(all contacts are now in the To: line, but only the original sender is
underlined)
4. Click "Send"

Actual result: Message is only sent to original sender, not to anyone on
the original CC: list. Neither Evolution nor the SMTP server complain.

Expected Results:
If there's only one matching contact, evolution should automagically look
up the email addresses when sending. If there's more than one matching
contact, or a matching contact has more than one email address, Evolution
should pop up a dialog where the user can choose the email address.  If
there's no matching contact, it should complain and go back to the compose
window.  Plus, if there's an error sending the message, it should also go
back to the compose window, not let the message rot in Outbox.

This on 1.1 snapshot.