Mail services like maileo commonly support standard email protocols such as IMAP for syncing mailbox contents and SMTP for sending mail. Webmail availability depends on the service configuration and product setup available in your account.
Your account details or setup instructions should be treated as the source of truth for the exact connection methods you should use. If you are setting up a third-party mail app, use the official hostnames, ports, and encryption requirements shown there.
When in doubt, test with one client first before rolling the settings to multiple users.