For both incoming and outgoing mail server put mail.yourdomain.com.** (Optusnet customers see below)

Our outgoing SMTP server requires authentication. Please ensure you enable it in your mail client, please see the related knowledgebase article to enable it for your particular email client.

**Note: If you are an Optusnet customer, Optusnet blocks Port 25 which is used for sending email. In this case, you will have to refer to Optusnet to obtain these details.