I suspect that your smtp server does not work when you are connected to the afrihost network.
You need to change the outgoing mail server to smtp.afrihost.co.za which works on our network and does not require authentication.
Alternatively, use your previous internet connection for your emails.
If you require further assistance, please
send a message to our WhatsApp helpline: https://whatsapp.afrihost.com
or visit our Help Centre: https://help.afrihost.com/
or see our FAQ page: http://faq.afrihost.com