Eu presumo que você não tenha configurado para armazenar uma cópia em seus itens enviados?
As configurações podem depender das configurações da sua conta (como o Exchange / imap / pop3)
Nas páginas do Office.Microsoft:
Change where sent messages are saved when using an IMAP e-mail account
In Microsoft Office Outlook 2007, you can specify where sent items are saved for your IMAP e-mail account. For example, if you are at work and add a personal e-mail account to Outlook, you can configure your sent items to be saved in the Sent Items folder of the data file or in a Personal Folders file (.pst) for your personal account.
NOTE The first time you send an e-mail message with your IMAP account, you are prompted to choose the folder where you want sent items saved.
- On the Tools menu, click Account Settings.
- Select an e-mail account that is not an Exchange account, and then click Change.
- Click More Settings.
In the Internet E-mail Settings dialog box, click the Folders tab.
To choose a custom folder for saving your sent items, click Choose an existing folder or create a new folder to save your sent items for this account in.
- Click a folder to save the sent items in, or click New Folder.
By default, the sent messages from all your accounts are saved in the default Sent Items folder in Outlook. If you have an Exchange account in your Outlook profile, the default folder is Sent Items in your Exchange mailbox.
Click Choose an existing folder or create a new folder to save your sent items for this account in, expand the folder list, and then click a folder. Usually, you choose Sent Items in the data file for the account that you selected.
NOTE You should first make sure that you are subscribed to the Sent Items folder so that it will appear in the Internet E-mail Settings dialog box as described in step 4. For information about how to subscribe to IMAP account folders, see the See Also section.
