Outlook Express not protected from Viruses !!!

Hello:

I need help if possible regarding my AVAST program.

I went into Outlook Express to check my E-mail and there was a strange E-mail, where I had to "Block Sender" and delete. Outlook Express is not like Yahoo mail, where you have to click in order to see your E-mail, but Outlook Express mail is already open and leaves you naked for Viruses to infect your PC, so;

After I closed OE, there was a message from AVAST on my desktop that said this:

AVAST has detected a secure connection from your mail program (process msimn.exe) to the POP server 67.195.135.148 (yahoo,com). This type of connection cannot be checked for viruses. Please disable SSL/TLS in your mail client so that the Mail Scanner can scan your mail. The Mail Scanner will provide the SSL/TLS security itself, so;

After closing that message box, I went over to my Yahoo mail to find the last message I received from CNET helping with another Topic I had posted, but before I could click on anything, another AVAST message popped up that said, Trojan Horse Blocked.

I immediately ran a AVAST Quick Scan and no infections were found.

I also ran Malwarebytes and no infections were found.

Can someone tell me how to set up the AVAST E-mail Client for OE to scan my E-mail ???

I have a DELL
Systems Type: Dimension 3000
Win-XP Home Edition

Thank U !!!

simplee55