send a "thank you" to this guy:
http://www.geekzone.co.nz/user_public.asp?user_id=38490
1. Create a new email account. The account should be POP3, even if your email account is IMAP (this way you won't have another accoun on your Mail Folders). Fill in the incoming email servers, outgoing email server (with your secondary SMTP server), and User name. Don't put your password. Go to More Settings and put a suitable name for this account (like Send Email from Home), and all the info required for your SMTP server, if it requires login and/or secure connection.
2. After creating it, it'll attempt to download your emails. Don't provide your password, just clic Cancel.
3. Go to Tools ===== Send/Receive ======= Send/Receive Settings ====== Define Send/Receive Groups. You'd probably see only one group (All Accounts). Click Edit, and on the new window choose your new account on the left menu. There is an option that says "Receive mail items", you need to uncheck it. Clic Ok.
This last step is used so Outlook will not attempt to download emails using your secondary account. This way every time you click on Send/Receive, Outlook will receive email through your "primary" account and send email through the primary and secondary account. When writting an email you'll see a button below Send, that allows you to define (select) which account to use to send the email, so depending on your location you'll choose one or the other.
