Is your iPod touch not able to send or receive mail as expected?
These tips will help you resolve most common email issues.
About Gmail and Deleted Messages:
Messages in a Gmail account could be permanently deleted after 30 days if you:
Are upgrading from software version 1.1.2 to 1.1.3 and had created the account using the Gmail preset.
Create a new Gmail account after upgrading to 1.1.3 using the Gmail preset.
In both cases, when you delete a message, the message will be put into the Gmail Trash (the Trash folder that you can see when you access Gmail via the Google web site) and will be purged after 30 days.
To avoid this and to "archive" deleted messages you can create an "Other > IMAP" account and configure it for Gmail by manually entering your account settings. In this configuration, deleted messages will be moved to a different folder that isn't automatically purged after 30 days.
Connectivity:
Verify you have an active Internet connection using Wi-Fi. You can test the connection by using any Internet-based application on iPod touch including Safari, Stocks, Maps or Weather.
iPod touch will display the Wi-Fi 
icon if it has an active network connection.If you don't see an active connection, or are unable to use any of the Internet-based applications, try these articles:
Tips when using Wi-Fi
Wi-Fi information and settings
What if I don't see the Mail, Stocks, Maps or Weather icons?
Mail Settings:
Check with your ISP to verify you have the correct email account settings. Some ISPs have special settings for using mail outside of your home network that are different from the settings that are used inside your home network.
An example of an outgoing mail server:
smtp.myisp.net
Example incoming mail servers:
pop.myisp.net or mail.myisp.net
Example user names:
username or username@myisp.net
Click here for advanced SSL and port settings.
For more information on email account setup, click here.
Setup on iPod touch:
Try setting up your email account on iPod touch instead of syncing it from your computer.
From the Home screen choose Settings > Mail > Accounts > Add Account.
Choose your email account type: Y! Mail (for Yahoo!), Gmail, .Mac, AOL, or Other.
Enter your ISPs Mail settings.
Check your password:
iPod touch hides your password for security purposes and shows only bullets instead of characters. It may be hard to see if you accidentally typed the wrong password. You may want to try typing your password again, entering it slowly and fully pressing down on each key down to verify that you typed it in correctly.
