Overview
mail.example.com
Please ensure you are only using your mail server name when connecting. This should be one of the following, depending on if you're using IMAP or POP to connect:
- imap.dreamhost.com
- pop.dreamhost.com
If you need further help
In rare cases, Mac OS may retain past SSL certificates despite the Mail account having been removed and Keychain Access being emptied of related certificates and passwords. If you find that any of the above steps do not resolve the issue, try removing your account completely from Mail, clear out Keychain Access of *mail.dreamhost.com certificates, and remove any saved passwords for your account. Then, reboot your Mac to flush any remaining configuration of the account from your system. Once the machine logs back in, you can proceed to re-add your email account in Mail.
Apple Support can provide the best assistance with Mac Mail issues. Apple technicians are the experts when it comes to Apple software.