I have a Yahoo! email address that I would like to be able to access using Mail 4.5 on my Mac (OS 10.6.8) and also on the Mail app on my iPhone4S (iOS 5.1.1). I tried to do this without success. Is there a way to do it? Where can I fine a step by step instruction?

Set up an IMAP account in Mail. Here are the settings:

Account type: IMAP
Incoming Server - imap.mail.yahoo.com
Outgoing Server - smtp.mail.yahoo.com
Incoming Port - 993 (requires SSL)
Outgoing Port - 465 (requires SSL)
User name: full email address (for example, bill@yahoo.com)
Password: the password you log in to Yahoo! with.

Thank you for such a complete answer. Before I try it, I need to ask one question. I accidentally set up an IMAP account on Gmail and it would not let me permanently delete email sent to it. The darn things(messages) kept reappearing. I went to the Gmail part of Google and thought I had taken care of it, but it would not let go. Is that typical of an IMAP account or did I encounter some kind of bug or did I miss something?

I have three IMAP accounts and Google is the ONLY one that does that.

I have found I can clear the messages out by logging onto the Google webmail interface and deleting the messages in each of the individual IMAP folders as well as the IMPORTANT folder and the INBOX. A real pain but it does prevent the mail from coming back again and again.

The way IMAP works, the messages are stored on a server. When you read a message on your computer, the message is copied on your computer so you can read it, but it stays on the server. The idea behind that is that you can check your messages from anywhere--a cell phone, your home computer, your work computer, whatever--and not lose any messages.

When you delete a message, you delete it from your computer. Whether or not that deletes it from the server depends on your mail settings. In Mail.app, go to Mail Preferences, click Accounts, click the IMAP account, and then hit Mailbox Behaviors. There are a bunch of options there for what to do with a mail message you delete.

If you turn on "Store deleted messages on the server," messages you delete will only be removed from your computer; they will stay on the server, ready to re-appear again. You might use this option for, say, an iPad or iPhone, where oyu don't want to delete the messages forever (because you want them to be on your desktop system) but you don't want them filling up limited storage space on the iPad or iPhone.

If you turn on "Move deleted messages to the Trash mailbox," it will make a folder called Trash on the server and put them there. They won't actually be removed, but they won't be in your inbox either.

If you want them to disappear totally and forever when you delete them, choose the option "Permanently erase deleted messages when: quitting mail."

Dear Tacit and Joemikeb:

Google and Apple should pay you good money for the privilege of inserting your posts in this thread directly into their instructions. If they had done that when I first got into this project, you would have saved me a full working day and a bad attitude. Thank you. It is exactly what I needed. I just wish I were competent enough to return the favor sometime. Again, thanks for the assist.

JoBoy

Here's a follow-up of my adventures with the Yahoo IMAP account. It's working perfectly and as advertised. It will be a very long time before I do Gmail IMAP.

Thank you both again. Your assist was great!