OK I see what you are trying to do. You basically would like email alerts for gmail. Since we cant mess with the Imap or pop3 settings yet on our phone you wont be able to do it that way.
But there is another way. Log into your gmail account on the computer. On the top right of the window you will see a "settings" tab. Click on "settings" then then click on "Forwarding and POP/IMAP". Chances are that you have already been here if you have looked into IMAP for gmail. Dont mess with the IMAP settings. Instead put a check in the spot for "Forward a copy of incoming mail to " and then enter your email address as your 10 digit phone number "
1234567890@txt.att.net" and leave the setting to keep a copy in Gmails inbox. Then down below select save changes.
Now when someone sends you an email to your gmail account a copy will stay there (including attachments) and a text version will be sent to your phone. Then you can log into gmail on your phone and read it again and then reply if you desire.
I have my (imap)gmail and (pop3/IMAP) comcast set up the same way. I get instant emails through a text and dont even have to open gmail or mobile email to read them. Works great as long as you have a text messaging plan. Let me know how it works for you.
You can also change your email address from
1234567890@text.att.net to
1234567890@mms.att.net and you will be able to see the attached pictures. I just figured this part out and it is way cool. Its better than mobile email on our phone cause now i can see some attachments.