Use the incoming and outgoing server settings provided by the mailbox host.

• Enter the mailbox address and, when different, the login username.
• Use an app password when the provider requires one for IMAP or SMTP access.
• Enter the IMAP host, port, and security mode for incoming mail.
• Enter the SMTP host, port, and security mode for outgoing mail.
• For an alias, set the SMTP envelope sender to the primary mailbox address if your provider requires it. Leave it blank otherwise. Some providers display the primary mailbox as sending on behalf of the alias.