Using Gmail on iPhone with alternate reply address.

It can be useful to have a subset of mail directed to a Gmail IMAP account to be retrieved with your iPhone.
I do this by duplicating a subset of my incoming mail to my gmail account, as well as depositing it to my standard account.
I want to maintain my standard account for all replies.

Here is the process:

In Google Gmail:
Select settings -> accounts
Add a second e-mail address to be associated with your G-mail account.
Set that account as the default reply-to address.

Your Gmail settings -> account tab will look something like this:
  Send mail as:   John Doe <firstname.lastname@gmail.com>         make default    edit info

                  John Doe <john@ispyouuse.com>                   default         edit info    delete


On the iPhone:

Delete your existing Gmail account if you have one.
It is IMAP so you won't lose any data.
Delete by settings -> mail, contacts, calendars / select Gmail account and "delete"

The "trick" is to set up an account using "other" under mail, not "Gmail".
Create a new account like so:
Under mail create an account and select "other"
(or add account under settings -> mail, contacts, calendars -> add account)

Use these settings:

Imap Account Information
Name  John Doe
Address  john@ispyouuse.com
Description  My Gmail Account

Incoming Mail Server
Host Name  imap.gmail.com
User Name  firstname.lastname
Password:  ........

Outgoing Mail Server
SMTP smtp.gmail.com

Make sure that "IMAP" is selected (should be by default).