Email Center Pro doesn't specifically require TLS but if your email service provider has disabled TLS, they may have also blocked the port that is normally associated with TLS connections as well. You may need to communicate with them to find out which port you should be using now for POP3 connections via SSL. Once you have their updated SSL port recommendations, you should update that setting within the POP configuration in Email Center Pro to resolve the problem.
That said, the best recommendation that we can give to immediately resolve this problem is to switch the way that you're getting email into your Email Center Pro account (read Pop vs Forwarding). This involves setting up your mail server to forward a copy of all new email messages directly into Email Center Pro via your mailboxes direct address see below) and disabling the POP connection within the Email Center Pro account.
The result of such a change is a more reliable transfer and faster delivery of email messages into your inboxes. This is because the POP checker can only check for messages every 10 minutes while forwarded email messages arrive in the inbox almost instantaneously.