#15 Add msg-id to headers

[Geoff Osbaldestin]

I have within my use of this excellent component used
an DNS Lookup to allow sending direct to the
destination email domain.
As this is not using a relay, can the component
auto-generate a messageid.

The reason for this is some anti spam software (in
particular) gives at score for emails where the server
generates the msg id
For Example.
I sent a html formed email (no attachments) to myself
(using a PostFix / Spamassasin server) and if created
the following report:
Content analysis details: (5.2 points, 5.0 required)

pts rule name description
---- ----------------------
--------------------------------------------------
1.0 HTML_IMAGE_ONLY_12 BODY: HTML: images with
1000-1200 bytes of words
0.0 HTML_MESSAGE BODY: HTML included in message
0.7 HTML_TABLE_THICK_BORD BODY: HTML table has thick
border
0.1 HTML_70_80 BODY: Message is 70% to 80%
HTML
0.1 MIME_HTML_ONLY BODY: Message only has
text/html MIME parts
3.3 MSGID_FROM_MTA_SHORT Message-Id was added by a relay

The original message was not completely plain text, and
may be unsafe to
open with some email clients; in particular, it may
contain a virus,
or confirm that your address can receive spam. If you
wish to view
it, it may be safer to save it to a file and open it
with an editor.

Most items I think are fine, though the total score
meant that in a default spam assassin installation the
email was flagged as spam.
If you look at rfc0822
(http://www.sendmail.org/rfc/0822.html#3) I am sure you
have hence the comments
if says:
msg-id = "<" addr-spec ">" ; Unique
message id
I am just looking at the impact of impementing this.

[Ian Stallings]

Logged In: YES
user_id=83842

I'll look into this. This will be an easy addition in
MailMessage.cs