Have you checked the iOS outbox? I've been told they sometimes get stuck there.
One thing to keep in mind: When it does arrive in your inbox, it will be a jpeg of the shape (the only way to get a vector is to access your shapes from the Libraries in our desktop (PS, Ai, iD) or mobile (Draw) apps.
To check to see if it's an email error from your device, or just to get it from another source, check this out:
1. Go to your CreativeCloud assets online: http://assets.adobe.com
2. Select the section called "Library" (where Shape images are stored currently)
3. If you haven't set up custom libraries, check the Basic Starter library, and you'll find several resources in there that you can use in CC apps. Here, you can do a bunch of stuff, including emailing from your different send location, like your desktop/laptop.
Remember, if Shape is supported in your CC app's library panel, you don't need to email it to yourself, just grab it from the library panel.
Here's how in IllustratorCC: Capture shapes to use in Illustrator | Adobe Creative Cloud Mobile Apps Tutorials
note: Currently, the email sends the .png result. Unless you use libraries in CC apps, you get the rasterized image, not the vector file.