Stop spam, phishing, ransomware, and malware before they reach your inbox — with enterprise-grade filtering, email continuity, and compliance archiving powered by N-able Mail Assure.
Over 90% of cyberattacks begin with a phishing email. Spam isn't just an annoyance — it's the primary delivery mechanism for ransomware, credential theft, and business email compromise. A single missed phishing message can cost a business tens of thousands of dollars. CSP's managed email filtering stops threats before they ever reach your inbox.
CSP's email spam filter service is built on N-able Mail Assure, an enterprise-grade cloud email security platform trusted by managed service providers worldwide. Mail Assure combines machine learning, real-time threat intelligence from over 23 million mailboxes, and multi-layer filtering to stop spam, phishing, malware, and ransomware with near-perfect accuracy — before any harmful message reaches your users.
Unlike basic spam filters built into email providers, Mail Assure provides dedicated inbound and outbound filtering, email continuity during server outages, long-term encrypted archiving, and full SPF/DKIM/DMARC authentication support — a complete email security stack managed by CSP on your behalf.
Mail Assure delivers a complete email security and management platform — not just inbox filtering.
Every inbound message passes through Mail Assure's multi-layer inspection engine — combining machine learning, real-time threat feeds, and collective intelligence from 23 million mailboxes to identify and block spam, phishing, and malware before delivery.
Mail Assure also scans outgoing messages from your domain — catching infected machines sending spam without your knowledge, preventing your domain from being blacklisted, and protecting the sender reputation that your deliverability depends on.
If your mail server goes down — whether due to an outage, migration, or maintenance — Mail Assure keeps your email flowing through a fully branded web portal. Your team can continue sending and receiving messages without interruption, and everything syncs automatically when your server comes back online.
Every inbound and outbound message is archived in encrypted long-term storage with unlimited capacity. Configurable retention policies support multi-year compliance requirements, and messages can be searched, queried, and exported quickly — essential for legal holds, audits, and regulatory compliance.
Mail Assure enforces SPF, DKIM, and DMARC — the three email authentication standards that prevent criminals from forging your domain or impersonating your executives. Business Email Compromise (BEC) attacks that try to spoof your CEO or CFO are stopped at the gateway.
Suspicious messages are quarantined for review rather than silently deleted. Users can access their quarantine through Mail Assure's Private Portal, review held messages, and release legitimate mail themselves — giving your team control without burdening your IT staff with false-positive tickets.
We handle the entire setup and ongoing management — no configuration required from your team.
CSP points your domain's MX records to Mail Assure and configures inbound and outbound filtering policies. For Microsoft 365 customers, we connect via OAuth for seamless integration. The entire setup typically takes less than an hour with zero email downtime.
Mail Assure immediately begins filtering all inbound and outbound email. Spam, phishing, and malware are blocked before reaching your mail server. Suspicious messages go to quarantine — your users get clean inboxes from day one.
CSP monitors your mail flow, quarantine activity, and filtering performance. We tune policies as your mail patterns evolve, manage allowlists and blocklists on your behalf, and deliver regular reports showing what threats were stopped and how your email health is trending.
A complete managed email security service — filtering, archiving, continuity, and ongoing management by CSP.
CSP's managed email filtering service is priced per mailbox at a flat monthly rate. We handle setup, configuration, and ongoing management — your team just gets clean, safe email from day one.
Schedule a Free Assessment (559) 251-7767Per-mailbox flat-rate pricing · Works with any email provider · Local Fresno support
If your business relies on email, it needs proper protection. These industries have the most to lose from a phishing attack or compliance gap.
Law firms and CPAs handling confidential client communications and regulatory retention requirements
Clinics and practices with HIPAA email requirements and patient data to protect
Farming operations and businesses targeted by invoice fraud and vendor impersonation scams
Every organization that uses email — phishing doesn't discriminate by industry or size
Email filtering stops threats at the gateway. Managed EDR stops threats that make it past — on your endpoints. Together, they give your business two layers of protection covering the most common attack paths. CSP manages both under one agreement.
Most phishing attacks succeed because there's nothing in place to stop them. CSP's managed email filtering changes that — from the moment we turn it on.