Trend Micro Email Security enables you to add SPF peers to the
ignored list. If SPF is enabled, Trend Micro Email Security
ignores the SPF peers that are included in this list, and does not perform a
verification for these peers.
Go to Inbound Protection > Domain-based Authentication > Sender Policy Framework (SPF).
Click Add Ignored Peer.
In Ignored Peer field, type a sender domain name, IP
address or CIDR block that you want to ignore for verification.