Yes—certain mailbox item types and properties can fail or degrade during OLM→PST moves due to client/version feature gaps, format differences, and limits in how Outlook for Windows interprets Mac‑specific data, so testing and targeted tool settings are essential to preserve fidelity. https://timessquarereporter.com/news/could-version-specific-mailbox-item-types-fail-during-olm-to-pst-migration