- You require enterprise-grade security assurances and the vendor cannot or will not provide documentation (SOC 2, ISO 27001, SSO/SAML, SCIM, audit logs).
- Your outbound operations are mission-critical and cannot tolerate downtime, delays, or sender disconnects that could materially impact revenue.
- You are evaluating a lifetime/one-time deal and are concerned about long-term vendor sustainability inherent in some non-recurring commercial models.
- You require advanced deliverability diagnostics (inbox placement testing, blacklist monitoring, domain health analytics) and prefer a vendor that documents these capabilities explicitly.
- You need mature agency governance features (client partitioning, per-client permissions, reporting, and SLAs) that are proven in production.