You can load in an activity stream using the CB Activity Bot anywhere that supports Joomla content prepare. Example as follows.
[cbactivity:activity asset="profile" paging="false" paging_first_limit="5", paging_limit="5" create="false" /]
The above for example should show their first 5 activity entries from their profile activity stream. Edit "Content - CB Activity" within Extensions > Plugins and review the description carefully for further usage information. I've no idea if this will work in AcyMailing though, sorry.