For those who are NOT technically savvy like myself, I am posting this to maybe help someone. I just had the problem of my email suddenly not sending any messages. (Sending'reported error (0x800CCC78). I have Comcast, and use Windows 7 on my laptop.
To fix this, I went to the Tools tab in my email, Account Settings, Clicked on my email address under where it says "Name," Click "More Settings" button on lower right, select "Outgoing Server" tab, and checked the box by "My outgoing server (SMTP) requires authentication." Then click OK, and it should work.
To fix this, I went to the Tools tab in my email, Account Settings, Clicked on my email address under where it says "Name," Click "More Settings" button on lower right, select "Outgoing Server" tab, and checked the box by "My outgoing server (SMTP) requires authentication." Then click OK, and it should work.
