This article was created in response to a support issue logged with K2. The content may include typographical errors and may be revised at any time without notice. This article is not considered official documentation for K2 software and is provided "as is" with no warranties.
SmartActions do not seem to work for users using external email addresses.
You receive a notification email and respond to it with a SmartAction (Approve / Reject) but K2 does not take action and ignores the response, even though you have linked your external email address in Active Directory.
In this case you are most likely using an email domain managed by an external email provider (for example Gmail) and the internal Exchange server marks all incoming emails with a header of spam level 0. It should have a level of -1 meaning authenticated user. Level 1 means spam.
You will have to find a way to either integrate your external domain with your internal Exchange server, or disregard email security and flag all incoming mail from that domain with a Spam Level of -1.
Please note: Disabling email security is not recommended.