Send emails from @yourdomain.com account using current email address with Outlook Express
These instructions outline how to use Outlook Express to send emails from an existing email account, but look as though they have come from your domain name email account.
Open outlook express
Go to tools > accounts
Click the mail tab select the account that you wish to send emails with @yourdomain.com from
Click on the properties button. Change the email address to name@yourdomain.com and then change the reply address to name@yourdomian.com
Press the OK button on the "Your Account Properties" window and click the close button on the "Internet Accounts" window, and you are done