Challenge

For a bank, email security is not limited to spam filtering or mailbox protection. Attackers often try to abuse trusted financial brands by impersonating executives, customer service teams, payment teams, alerts, statements, or digital banking communications. Banque Postale du Congo needed to reduce this domain-level impersonation risk across its main domain and subdomain infrastructure while maintaining control over high-volume email flows and existing on-premise MX security.

Why Skysnag

Banque Postale du Congo already had mail security controls in place, including robust MX protection and MTA-level security. The remaining gap was domain trust: making sure only authorized systems could send on behalf of the bank, and that unauthorized or suspicious sources could be identified, monitored, and controlled.

Rollout model

The rollout was designed around banking continuity. Instead of disrupting the bank’s existing mail infrastructure, Skysnag would sit as a domain-authentication and trust layer, helping the team map legitimate senders, review authentication posture, and move toward stronger protection without breaking critical email flows.

Rollout steps

1. Map legitimate senders – Identify the systems sending email for the main domain and subdomains, including internal infrastructure and third-party platforms.
2. Close authentication gaps – Review SPF, DKIM, DMARC, MTA-STS, and TLS reporting posture to detect weak points and unauthorized sources.
3. Move toward enforcement – Strengthen policies gradually so the bank can reduce impersonation risk without interrupting legitimate banking communications.

Results and proof signals

The value of the project is measured in risk reduction, control, and operational visibility. For a bank, the goal is not only to improve deliverability, but to make it harder for attackers to misuse the institution’s trusted domains in phishing, fraud, or brand impersonation campaigns.

Results stats

What this means for public and private financial institutions

Banks often invest heavily in perimeter, mailbox, and transport-layer security, but attackers can still exploit weak domain authentication to impersonate the brand. This case shows why financial institutions need a dedicated domain-trust layer that complements existing MX and MTA security, protects customer confidence, and gives security teams clearer control over who is allowed to send as the bank.