The Default Gravatar Picture Rules Needs to Be Enforce

[felicianotech]

When you include a default image, Gravatar will automatically serve up that image if there is no image associated with the requested email hash. There are a few conditions which must be met for default image URL:

1. MUST be publicly available (e.g. cannot be on an intranet, on a local development machine, behind HTTP Auth or some other firewall etc). Default images are passed through a security scan to avoid malicious content.
2. MUST be accessible via HTTP or HTTPS on the standard ports, 80 and 443, respectively.
3. MUST have a recognizable image extension (jpg, jpeg, gif, png)
4. MUST NOT include a querystring (if it does, it will be ignored)