GMail account - remove "on behalf of"

It has just become apparent to me that the gmails I was sending out through other account names have had "on behalf of" added to each one! Bloody hell Google. I could have sworn there was a time when this was not there? Is there any way to remove this annoying extra and preserve my anonymity please? Thanks for any help!

Torqay

To remove "on behalf of" and your Gmail address from messages you send in the Gmail web interface using another email address:

Follow the Settings link in Gmail.
Go to the Accounts tab.
Click edit info next to the desired email address.
Click Next Step ››.
Make sure Send through example.com SMTP servers is selected under Send mail through your SMTP server?.
Enter the SMTP server name for the email address under SMTP Server:.
Enter your email user name (usually either the full email address or what Gmail has already entered) under Username:.
Type the email account's password under Password:.
If the SMTP server supports secure SSL connections, make sure Always use a secure connection (SSL) when sending mail is checked.
Verify the SMTP port is correct: with SSL, 465 is the typical port; without, 587.
Click Save Changes.

Source

P.S: If you really want to "preserve your anonymity" you should avoid anything Google like the plague!

I completed the first few steps but there's nothing in the settings area about SMTP servers. Even when I click "Edit Info" next to the email address in the accounts area there's no such option!