Richard,
Sorry, but it seems that this issue has NOT been resolved with “Sharing” on Jetpack when “Email” sharing is enabled. The user reporting it to you above (Michael) is running the current versions of both WordPress 3.8.1 and Jetpack 2.9.2. I did not see a fix or solution listed. Therefore it does not seem like this issue is “resolved” quite yet, unless you know something that we do not. I have seen this exact issue occur. I think the only way to avoid it right now, is to go into “Settings” -> “Sharing” -> “Configure” and then drag-n-drop the “Email” icon from “Enabled Services” into the “Available Services” area under the “Sharing Buttons” section.
Is the Jetpack team aware of this vulnerability as revealed in this article: https://fossforce.com/2014/03/wordpress-jetpack-sharing-plugin-exploited-by-spammers/
If so, please let us know and when they estimate to have a fix or upgrade to Jetpack to prevent this issue.
Thank you so much for your help.
