@Dons2000 wrote: From the community posts it looks like all of TPG email server clients are receiving the security certificate error.   I'm getting the same pop up error message when I open Outlook (Office 2016) to view my TPG emails. This started today.   The pop up warning states; "The server you are connected to is using a security certificate that cannot be verified. The target principal name is incorrect." When you view the security certificate it indicates it is issued to "mail.wondercom.com.au" and expired 7/05/2017.   According to web searches, "Wondercom" appears to be an old subsidiary business of TPG. If that is the case, why is TPG all of a sudden today, using a subsidiary company's expired security certificate on TPG's mail server????   This needs to get fixed now.  I faced similar kind of issue last time, I am still searching for some proper solution ... View more