I recently learned about the known issue with the release of VMware Content Locker version 4.13 on iOS. Since we do enforce the email attachment policy to make sure it only opens in VMware Content Locker, I took the steps per this link to correct it. Without doing so, your users may get the error below when opening email attachment with Content Locker version 4.13 on iOS:

There are two parts to address this known issue. First, we need to publish the native mail app as a public app. Then, we need to add the native mail to the allowed applications list of our Data Loss Prevention policy.

Browse to APPS & BOOKS -> Applications -> List View. Then click on Public tab and Add Application.

Follow the remaining prompts to add the native mail app.

In this prompt, make sure to select United Kingdom next to Country (since United States does not list native mail client). Then click Select next to the Mail app.

Click Save & Publish. There is no need to assign this app to anyone.

Now, navigate to GROUPS & SETTINGS -> All Settings -> Apps -> Settings & Policies -> Security Policies.

Scroll down and expand Data Loss Prevention.

Under Allowed Applications List, search for Mail (Apple iOS). Then click Save toward the bottom of the page.

Enjoy and as always. Stay mobile!