There is nothing to go on here. Please post more clearly and with more
detail.
By "Group of Contacts" are we to assume you actually meant a Distribution
List?
If so, how did you create this DL and in what information store?
By what method did you select this DL as the recipient?
Over what transport did you send this message?
You are using a beta. Steps to repro your behavior are essential because no
one else has seen it.

Signature
Russ Valentine
[MVP-Outlook]
> 1. Create "Group of Contacts" in the Outlook 2007 using Contacts
> 2. For Eg: 'BalajiOwn' is the group name and it contains three contacts
[quoted text clipped - 9 lines]
> But this message still stays in the Outbox and doesn't turn to move in
> SentItems.
Balaji - 30 Jun 2006 23:13 GMT
1. ‘Ctrl+Shift+L’ to create ‘Distribution List’
2. Click Members tab(by default Members Tab is enabled)
3. Type name in the ‘Name’ say ‘BalajiOwn’ for Distribution list (Group)
4. Click ‘Add New’ Members
5. Enter ‘Display Name’ and ‘E-Mail address’;
6. Click ‘OK’
7. And repeat step 4 to 6 for more contacts to add into ‘Distribution list’
8. Click ‘Save & Close’ Distribution list
9. Click ‘Mail’ tab
10. Click ‘New Message’
11. Type ‘BalajiOwn’ in the To… address;
12. Type ‘Hi’ in the ‘Subject:’ and Hello in the body of message
13. Click ‘Send ‘ button in the mail message
Issue:
It is sending this message to all the mail ID’s which are tagged in this
particular distribution list (‘BalajiOwn’) but the message stays in the
‘OutBox’ folder and not moved to the ‘Sent Items’ folder
Contact: bwithsun@hotmail.com
> There is nothing to go on here. Please post more clearly and with more
> detail.
[quoted text clipped - 19 lines]
> > But this message still stays in the Outbox and doesn't turn to move in
> > SentItems.
Russ Valentine [MVP-Outlook] - 01 Jul 2006 02:12 GMT
I would never expect that to work in a beta.
DL's that aren't based on members who reside in the Contacts folder often
don't work even in released versions.
Most users have abandoned DL's because they are so unreliable.

Signature
Russ Valentine
[MVP-Outlook]
> 1. 'Ctrl+Shift+L' to create 'Distribution List'
> 2. Click Members tab(by default Members Tab is enabled)
[quoted text clipped - 40 lines]
>> > But this message still stays in the Outbox and doesn't turn to move in
>> > SentItems.