Email grouping can sometimes be affected by how messages are threaded or grouped based on their content. In Microsoft Purview eDiscovery, for example, email threading analyzes messages to determine if they contain unique content or if they are part of a chain. This means that even if emails are under the same topic, they may not be grouped together if they have unique content or if the threading logic identifies them differently.
Additionally, in the context of grouping emails, if there are changes in how emails are categorized or if the grouping settings have been altered, this could also lead to some emails not being grouped together as expected.
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