What’s unique about corporate domains vs consumer ISPs?

Corporate email environments differ significantly:

Security gateways: Proofpoint, Mimecast, Barracuda, and others add filtering layers before messages reach Exchange or Gmail Workspace.

Stricter policies: Administrators configure aggressive filtering for security.

Quarantine: Messages may be held for admin review rather than delivered or rejected.

Custom rules: Organization-specific blocking or allowing.

Compliance requirements: Industry regulations may drive filtering decisions.

B2B senders face different challenges than B2C senders targeting consumer inboxes.

Corporate harbors have their own security teams with custom inspection procedures.