Avast! Web Shield blocks all email sent using the Windows 8 Mail app. It seems as if avast! does not recognize it as an outgoing email and scans it with Web Shield, resulting in a false positive virus detection. When I try to send, I get a popup message on the desktop stating the following:
avast! Web Shield has blocked a harmful webpage or file.
I tried excluding both the url and the process in the exclusion settings. The ‘URLs to exclude’ in the Web Shield Settings - Exclusions does not allow entering https, only http.
The only way that I’ve been able to send email from the Windows 8 mail app is to completely turn off Web Shield. I am able to successfully send email from the same account and settings using Mozilla Thunderbird. Avast! recognizes the email sent from Thunderbird as an outgoing email, scans it, and verifies that it is free of viruses.
You can upload files and report issues to avast here : http://www.avast.com/contact-form.php (select subject according to Your case)
you may add a link to this topic in case they reply here
The problem has been resolved by avast. I didn’t have to do anything differently. I was able to send an email today using the Windows 8 Mail app.
On the down side, it doesn’t appear that the Mail Shield scanned it for viruses because there was no message inserted at the bottom of the email stating that avast determined it was clean. But that’s a different topic!