It is possible to delete Emails based on a Tag applied to a Message and also after a certain age from Archive Manager?
As per Page 22 of the Archive Manager 4.4 Retention Policy Guide:
The collection of messages to be retained can further/also be narrowed by the set of tags in the Items tagged with field.
This field is visible only if the tags are defined within Archive Manager. Note that the flag tag is not listed in the Retention Editor.
String and Number tag policies with no value will function as a wildcard.