As part of a drive to improve security we will be phasing out support for insecure 'legacy' connection methods by the end of August 2014 or sooner for some servers.
We term a legacy connection where a client connect to our servers without the benefit of using encryption which allows for mail box credentials to be easily stolen.  

The settings for email are now;

incoming mail server: imap.quick.net.au, SSL encryption=on, port 995 (pop3)or 993 (imap) and authenticates with email address and password.
outgoing mail server: smtp.quick.net.au, SSL encryption=on, port 465 and authenticates with email address and password.

This replaced;

incoming mail server: mail.yourdomain.com.au, port 110 (pop3) or 143 (imap) and authenticates with email address and password.
outgoing mail server: mail.yourdomain.com.au, port 25 and authenticates with email address and password.

If you still have old settings like these we urge you to update to our current recommended settings. Doing so will ensure your mail accounts are far more secure from
hackers which may cause nasty disruptions to your work while the mess is cleaned up.  

For more details see our mail help articles located here

Failure to update to our recommended settings will may result in an inability to collect your mail until the settings are updated.