I'm guessing this isn't a bug since I haven't seen anyone else with this problem, but in my conversation emails, the avatars don't include the domain of my site. It just shows up as http://data/avatars/s/etc. Any ideas on what the problem could be?
I'm actually not sure when it started, it could have never been working I'd have to ask some of my members. All of my templates are up-to-date and the problem persists when I disable all my add-ons.
I've looked through the template helper code and this seems to be what's causing the problem. XenForo_Application::$externalDataUrl's value is just 'data' but I don't know how to fix it other than hard-coding my url into the helper.
I was actually able to narrow it down to a problem with Windows Live Email. I tried using a Live email here on the XenForo forum and had the same problem. Even after selecting to always allow images from firstname.lastname@example.org, the images are broken, with no domain in the image source (http://data/avatars/). It doesn't seem like there are different templates for different email services, so my guess is that Live email actively removes the domain from the emails. Can anyone confirm this?