The IRS/Treasury issued a Sources Sought/RFI for market research only, seeking information on commercially available enterprise inbound email retention, centralized search, and forensic analysis solutions for both legitimate and malicious email; it is not an RFP/RFQ and creates no contract obligation. The solution must integrate with existing Cisco IronPort/BCC infrastructure to preserve complete, unaltered inbound emails—including headers, content, metadata, and attachments—and operate independently of Outlook add-ons or client-side software, with on-premises, virtual, cloud, or hybrid delivery considered. Anticipated capabilities include support for up to approximately 1 million inbound emails per day, peak volume of about 150,000 emails per hour, about 22 TB per month, configurable 30–180 day retention, analyst search/quarantine/attachment review, Splunk and Splunk SOAR integration, high availability, 24x7 support, and federal security/compliance features such as FIPS-validated cryptography, RBAC, audit logging, IPv6, Active Directory/LDAP/SAML, and FedRAMP status for cloud offerings. The IRS anticipates a target implementation date of June 2027 and asks vendors to identify estimated delivery/implementation timelines and whether their solution could be operational by that date. Vendors should describe their COTS product, capability gaps or configuration needs, Cisco IronPort integration approach, Microsoft product dependencies, federal certifications/hosting/U.S.-citizen support, contract vehicles, and level of interest in a future requirement.