[Gmail-Users] SMTP Server Changes Sender's Email Address

Gmail is great. So it was too irresistible to avoid using
"SMTP.GMAIL.COM" as my SMTP server during my frequent travels. Thing
is, I need to have my emails appear as sent from my company's domain
(which only possesses a POP3 server), not me@gmail.com.

Gmail's SMTP server transforms my Outlook email details from
"me@mydomain.com" to "me@gmail.com". Is this a deliberate marketing
thing or did I miss something in Outlook's email account settings?

Once again, me@mydomain.com is specified in Outlook's email account
settings in the User Information email address, and the reply email
address, but still appears to the recipient as though sent by
me@gmail.com.

Thanks!