If you use Google Apps for your domain, sometimes you have a "group" setup, such as info@yourdomain.com.

Mail sent to info@yourdomain.com is then forwarded to the members of the group, such as chris@yourdomain.com.

The problem is that when you want to send an email from the info account, Gmail adds the "Sender" header which makes it appear to the recipient as:
"From: chris@yourdomain.com on behalf of info@yourdomain.com".

To solve this problem:

• Login to Gmail's web interface and go to your email "Settings".
• Go to the "Accounts" tab
• If you haven't already done so, add the account in the "Send Mail As" section
• Set the email address as  This e-mail address is being protected from spambots. You need JavaScript enabled to view it  (the group address)
• This is the important part: Choose "Send through Your Domain's SMTP Servers".
• The SMTP Server is smtp.gmail.com
• The Username is  This e-mail address is being protected from spambots. You need JavaScript enabled to view it  (don't put the group address here!)
• The Password is the sender's usual Gmail password
• Tick the "Always use a secure connection (SSL) when sending mail" box
• Change the Port number to 587 (ticking the SSL box will change it to 465, so do that step first)

I've done this and checked the email headers, there is no trace of This e-mail address is being protected from spambots. You need JavaScript enabled to view it mentioned. This means if the recipient replies to the email, it will get sent back to This e-mail address is being protected from spambots. You need JavaScript enabled to view it (which will then get forwarded to all members of that group, including This e-mail address is being protected from spambots. You need JavaScript enabled to view it ).

To get this working in Outlook, Thunderbird etc you still need to make the changes in Gmail's web interface. Then you can add the sender address like you normally would. If you skip the steps above and try to send through Outlook, it will add "On Behalf Of" to the headers.

To check if this worked, you can view the message source and look for:
"Sender: MyCompany < This e-mail address is being protected from spambots. You need JavaScript enabled to view it >".
This would mean it didn't work.
If you can't find any reference to the personal account in the email headers, then your personal address won't appear to any of your recipients (meaning you can keep your personal account hidden from your customers).

< This e-mail address is being protected from spambots. You need JavaScript enabled to view it > This e-mail address is being protected from spambots. You need JavaScript enabled to view it >

Hope this helps!