Q: how do i install P18-imap.mail.me.com on my computer?

Hello rayandvirginia,

It sounds like you are trying to setup an iCloud Mail account in a mail client on your PC. This article should provide you the settings you need to use to get that setup:

iCloud: Mail server settings for email clients

If that is not the case, can you be more specific about what you are wanting to do?

Thank you for using Apple Support Communities.