Posting permission
If you have an EchoMark Gmail integration set up for your organization, you'll need to be aware that EchoMark's Group posting permissions are stricter than Google's because Google's APIs do not give access to all permissions information for a given group. EchoMark bases its posting permissions on the roles that are allowed to post to a given gorup, and each group member's role - EchoMark does not have access to posting permissions that have been given on a per-user basis, outside the "role" construct.
To get around this, you can either give posting permissions exclusively through roles in Workspace, or you can enable certain users in your organization to bypass and override all posting permissions in the EchoMark UI - you'll want to use this sparingly, as it truly opens up posting to any group in the org.
Moderated groups
EchoMark does not support moderation in groups. If a group has moderation enabled, EchoMark cannot personalize marked copies for each recipient. You can skirt this issue by giving specific users in your organization the ability to bypass moderation.