Email not arriving from domain host

For the last 48 hours emails forwarded by my domain host have not been arriving in the inbox. Red triangle alongside the 2 email accounts yet my outlook email has not been having any problems. Emails arrive safely on my ipad. This is a new problem and I have checked settings with support team. Solution please

The red triangle indicates a connection problem. Go to Menu > Operations and look for any IMAP errors in the Log tab.