iOS 8 UIActivityViewController Mail does not send email attachments

Question

I am trying to share my custom type ".stccourse" via UIActivityViewController. I can Airdrop the file to my mac from my iPad but when I try to mail it, I don't get any file attachment. I do see the text as message body but no attachment. Following is my code:

    @IBAction func didTapShareButton(sender: UIBarButtonItem) {
    do {
        // Get course zip
        if let courseZipDict = try STCCourseManager.sharedInstance.getZippedCurrentCourse(), let courseZipData = courseZipDict["courseZip"] as? NSData {
            let fileManager = NSFileManager()

            // Write courseZip to Temp folder
            let filePath = NSTemporaryDirectory().stringByAppendingPathComponent("\(STCCourseManager.sharedInstance.currentCourse?.title).stccourse")
            try self.writeData(courseZipData, toFilePath: filePath)

            // Create activity view controller
            let shareVC = UIActivityViewController(activityItems: ["Course shared", NSURL(fileURLWithPath: filePath)], applicationActivities: nil)
            shareVC.popoverPresentationController?.sourceView = self.view
            shareVC.popoverPresentationController?.barButtonItem = self.shareButton
            self.presentViewController(shareVC, animated: true, completion: nil)
        }
    } catch {
        print("Failed with error: \(error)")
    }
}

I am not sure what am I missing here. Any help would be appreciated. Thanks

I have also added my custom type UTI to Info.plist:

<key>UTImportedTypeDeclarations</key>
<array>
    <dict>
        <key>UTTypeConformsTo</key>
        <array>
            <string>public.data</string>
            <string>public.archive</string>
            <string>com.pkware.zip-archive</string>
        </array>
        <key>UTTypeDescription</key>
        <string>STCCourse File</string>
        <key>UTTypeIdentifier</key>
        <string>com.vik.stccourse</string>
        <key>UTTypeTagSpecification</key>
        <dict>
            <key>public.filename-extension</key>
            <array>
                <string>stccourse</string>
            </array>
        </dict>
    </dict>
</array>
<key>UTExportedTypeDeclarations</key>
<array>
    <dict>
        <key>UTTypeConformsTo</key>
        <array>
            <string>public.data</string>
            <string>public.archive</string>
            <string>com.pkware.zip-archive</string>
        </array>
        <key>UTTypeDescription</key>
        <string>STCCourse File</string>
        <key>UTTypeIdentifier</key>
        <string>com.vik.stccourse</string>
        <key>UTTypeTagSpecification</key>
        <dict>
            <key>public.filename-extension</key>
            <array>
                <string>stccourse</string>
            </array>
            <key>public.mime-type</key>
                <string>application/myappname</string>
        </dict>
    </dict>
</array>