Graphic don’t come through on newsletter

Using mailpoet2. Newsletter graphics don’t come through, just text and boxes with question markets etc. Selecting “view this newsletter in your browser” yields a message that the website cannot be found does not found. But the name of the site given that cannot be found, is not the website from which the newsletter should have come from, but a variation on it. I can’t find anyplace in the mailpoet setup where the website is to be set. ????