1. use IMAP.
2. for “Incomming Mail Server” section. “Hostname:” while you can use ‘mail.example.com’ you will see a “server identity” warning when using SSL. This is because the certificate is issues to dreamhost rather than mail.example.com. To avoid the warning use the dreamhost version of the hostname for your mail cluster, see this wiki article to determine the actual hostname of your mail cluster. For “User Name” use your FULL email address. “Password” is of course your email password.
3. You MUST set up the outgoing mail server info. Use the same info as for incoming. Additionally, Use SSL: on, Authentication: Password, Port 587. Setting up Outgoing server info is not optional with dreamhost as the iphone/iPad screen seems to be suggesting.
4. Advanced Settings: Incoming settings: Use SSL: on, Authentication: Password, IMAP path prefix: / ,Port 993.
5. After you have successfully connected and can send and receive, go back to advanced settings and change the mailbox behaviors for Drafts, Sent, Deleted (trash), and Archive mailbox to the “SERVER” version of the folder.