Windows Live mail

Hello guys, I have just the Comodo firewall installed, product version5.9.219863.2196. I received and installed updates some days ago, one straight after the other with a day between them, since that update I find my windows live mail cannot send out via my ISP, mail will still go out via MSN, yet mail can come in from any of the two I use, both my ISP or MSN, just will not send on my ISP, have copied the live mail fault report as below to see if that gives any clues.
For information I am running Windows 7 Pro, 64bit.
Here is the fault report=

An unknown error has occurred.

Subject ‘testing.’
Server Error: 421
Server Response: 421 Cannot connect to SMTP server (, connect error 10060
Server: ‘
Windows Live Mail Error ID: 0x800CCC67
Protocol: SMTP
Port: 25
Secure(SSL): No

I have checked both the firewall and defence + and can find nothing to suggest that any part of live mail is being blocked, also it reports that live mail is accepted as a safe process.
Any clues as to where else I can look to sort this out?


Since posting the above, a Microsoft help page sent me in the right direction. Because I only have and use just the Comodo firewall, I use Avast anti-virus. It was the antivirus blocking mail out when it should only be scanning it. I have turned off the outward scan engine within Avast and all is now OK.
I hope this may prove useful for anyone else having similar problems.