Currently, most advanced mobile phone technology has more features and facilities. One of the features that are embedded in the mobile phone feature is push email. With a push email you do not need to browse to open email. This can save time and also save your balance. Some popular brand mobile phone such as Nokia and Sony Ericsson already supports push email. The following parameters are for setting push Yahoo email in general.INCOMING SERVER: imap.mail.yahoo.com
OUTGOING SERVER: smtp.mobile.mail.yahoo.com
The following example settings for push email on the Nokia 3230:
1. Open menu message -> Mailbox
2. Select Options -> Settings
3. Typethe name Mailbox, eg: Yahoo
4. Select the access point, eg: T-cells (choose your phone operator )
5. Type an email address, eg: xxxx@yahoo.com
6. Type the username, eg: myaccount
7. Enter a password, eg: 123456
8. Enter the Incoming Server: imap.mail.yahoo.com
9. Enter the Outgoing Server: smtp.mobile.mail.yahoo.com
10. Save
To download the email on your phone, enter the message and select Yahoo. Then email client will download e-mail headers in the mailbox Yahoo. Choose one. Email will automatically open to your mobile phone.

thnx for this usefull info :)
regards
IMAP is not push...
Can you use these settings in Mac mail?