Fax Server: Complete Guide (2026)

By David Thompson · Published March 24, 2026 · Updated June 8, 2026 · 11 min read

A fax server is the backbone of enterprise fax infrastructure — a centralized system that routes all inbound and outbound faxes across an organization, replacing the chaos of individual fax machines with a single, managed platform. Instead of walking to a machine, employees send faxes from their computer, email client, or any application, while every transmission is logged and auditable.

More than 80% of enterprises still rely on fax for business-critical communications. A properly configured fax server is how large organizations handle thousands of fax pages per day without paper jams, busy signals, or compliance gaps.

This guide covers everything you need to know: how fax servers work, the four deployment types, the top solutions for 2026, HIPAA requirements, and how to decide between on-premises and cloud.

What Is a Fax Server?

A fax server is a network-based system — dedicated hardware, software running on a server, or a cloud-hosted service — that handles all fax transmission for an entire organization from one place.

The core problem it solves: In traditional setups, every department needs its own fax machine, its own phone line, and its own toner supply. Faxes arrive on paper and sit unprotected in output trays. There is no audit trail, no encryption, and no way to send without physically walking to the machine.

A fax server eliminates all of that. Users send faxes the same way they print — via a virtual print driver, Outlook plugin, or web portal. Incoming faxes arrive as PDFs or TIFFs in an inbox, routed automatically to the right person or department. Every transmission is logged with timestamp, sender, recipient, and delivery confirmation.

How a Fax Server Works

Every fax server performs the same core sequence, regardless of whether it's on-premises or cloud:

1. Document input — The user "prints" to a virtual fax printer, sends an email to a fax number address, uploads via web portal, or triggers the server via API.
2. Format conversion — The server converts the document (PDF, Word, TIFF) to the ITU T.30 fax protocol format. For inbound faxes, it does the reverse: analog signal → digital PDF or TIFF.
3. Transmission — The server connects to the phone network via PSTN analog lines, T1/PRI circuits, or (increasingly) SIP trunks using the T.38 FoIP protocol for IP-based transmission.
4. Routing — Incoming faxes are automatically directed to the right recipient — by DID number, OCR keyword, barcode, or department rule — and delivered to their email inbox, shared folder, or EHR/ERP system.
5. Logging — Every transaction is written to an immutable audit log: sender, recipient, timestamp, page count, delivery status.

Types of Fax Servers

There are four deployment models. The right one depends on your organization's size, IT resources, compliance requirements, and budget.

On-Premises

The traditional model: server hardware and fax software deployed inside your data center. Your IT team owns installation, telephony hardware (fax boards, PRI lines), Windows Server licensing, and ongoing maintenance.

Best for: Large enterprises with existing on-prem infrastructure, complex EHR/ERP integrations, or strict data sovereignty requirements.

Watch out for: High total cost of ownership — server hardware, SQL licensing, fax board hardware, dedicated IT labor, and telephony circuits add up fast. Implementation typically takes days to weeks.

Examples: OpenText RightFax, FaxCore On-Premise, Biscom FAXCOM, XMediusFAX On-Premise

Cloud / SaaS

Fully hosted — no on-site hardware, no fax boards, no telephony management. Users access faxing via email or a web portal; the provider handles all infrastructure, redundancy, and failover.

Best for: SMBs, distributed or remote workforces, and any organization modernizing away from legacy on-prem. Fastest deployment (hours, not weeks) and lowest operational overhead.

Examples: mFax Business, eFax Corporate, etherFAX, FaxLogic, Esker Cloud Fax

Hybrid

On-premises fax server software combined with cloud-based telephony processing. Your organization retains software control and data ownership; the cloud handles the modem layer — eliminating local telco circuits and FoIP complexity.

Best for: Organizations mid-migration from on-prem, or those needing compliance control with cloud-level scalability and failover.

Examples: FaxCore "Partly Cloudy" (uses etherFAX for the modem layer), Esker Hybrid, OpenText Hybrid

Managed / Hosted

Dedicated fax server software running in a service provider's data center — identical feature set to on-prem, but IT management is handled by the provider. More control than pure SaaS, less operational burden than on-prem.

Best for: Organizations that want on-prem features without maintaining the infrastructure.

Top Fax Server Solutions in 2026

OpenText RightFax

The dominant enterprise on-premises fax server with the largest installed base. RightFax integrates deeply with SAP, Oracle, Epic, and Microsoft platforms — making it the default choice for organizations already standardized on the OpenText ecosystem.

The trade-off is total cost of ownership. On top of the RightFax license, you need Windows Server, SQL Server, fax board hardware, and dedicated IT staff. Many organizations are actively migrating off RightFax to reduce costs.

FaxCore

FaxCore positions itself as one of only two true enterprise fax server platforms (alongside RightFax) and offers genuine flexibility: on-premise, cloud SaaS, and hybrid options within the same product. It supports up to 120 ports per server and a distributed multi-server model for high availability. Usage-based pricing with no long-term contracts is a meaningful differentiator versus RightFax.

mFax Business

For teams that don't need a complex on-premises deployment, mFax Business delivers enterprise fax capabilities without the infrastructure burden. Plans start at about $9/mo (billed annually) and include:

• HIPAA-ready infrastructure with BAA available on every paid plan
• Virtual fax numbers with number porting
• Team accounts with role-based access
• Web dashboard for centralized send/receive management
• Delivery tracking and audit logs
• Developer API access included on every plan — see developers.mfax.to

Pricing is fully customizable: instead of rigid fixed tiers, you build your own plan with a live calculator — choosing the exact seats (1–35) and pages (200–5,000) you need and paying only for what you use ($3/seat + $4 per 100 pages). It's the right fit for healthcare practices, legal firms, and growing businesses that need reliability and compliance without a full IT deployment.

Key Features to Look For

Not all fax servers are equal. When evaluating options, prioritize:

Fax Server vs. Fax Machine vs. Online Fax Service

The economics have shifted significantly. A traditional fax machine with a dedicated phone line costs ~$40/month before supplies and maintenance. An on-premises fax server runs tens of thousands of dollars in total cost of ownership when you add server hardware, SQL licensing, IT labor, and telephony circuits. Cloud fax services start at $10–$25/month and require no infrastructure investment.

For most organizations evaluating fax infrastructure in 2026, cloud is the default unless on-prem integrations are mandatory.

Industries That Rely on Fax Servers

Healthcare

Healthcare is the largest fax server market by volume. Approximately 70% of all clinical communication still occurs via fax, rising to 90% when including EHR-linked faxing. Referral orders, lab results, prescription authorizations, insurance pre-authorizations, and discharge summaries all move over fax — often because the receiving end (a specialist office, insurer, or government agency) only accepts fax.

HIPAA is the critical compliance driver. Fax has a well-established compliance track record when proper safeguards are in place. Learn more in our guide to HIPAA-compliant faxing.

Legal

Courts at the state and federal level still require fax for emergency filings, pleadings, and certain motions. Law firms also use fax for client document exchange where email is considered insufficient chain of custody, and for serving opposing counsel in jurisdictions that mandate fax service.

Finance & Banking

Wire transfer authorizations, loan applications with physical signatures, mortgage closing documentation, and insurance claims all rely on fax in regulated financial environments. GLBA and PCI-DSS compliance requirements drive the need for encrypted, auditable fax transmission.

Government

IRS, SSA, and many state agencies require faxed documents for specific forms and benefits applications. Licensing boards, procurement departments, and law enforcement records requests are similarly fax-dependent.

HIPAA Compliance Requirements

A fax server is not automatically HIPAA compliant — you must verify specific safeguards are in place before transmitting any Protected Health Information (PHI).

Required technical safeguards:

• Encryption in transit: TLS 1.2 or higher (proposed 2026 HIPAA Security Rule update moves this from "addressable" to "required")
• Encryption at rest: AES-256 or equivalent
• Access controls: Role-based access control (RBAC) limiting PHI access to authorized users only
• Multi-factor authentication: MFA or SSO integration for all user logins
• Immutable audit trails: Logs of every send/receive event, user access, and administrative change — exportable for compliance review

Required administrative safeguards:

• Signed BAA: Any vendor that stores, transmits, or accesses PHI is a Business Associate. A signed Business Associate Agreement is mandatory before the first PHI fax. See our complete guide to BAAs for fax services.
• Documented policies: Written procedures for fax handling, misdirected fax response, and data retention
• Staff training: All personnel handling PHI faxes must receive HIPAA privacy training

For the full requirements checklist, see our HIPAA fax requirements guide.

How to Set Up a Fax Server

Cloud Setup (hours to days)

On-Premises Setup (days to weeks)

On-premises deployments require additional steps before any of the above: provisioning server hardware (or VMs), installing Windows Server and SQL Server, installing fax server software, configuring telephony (analog lines, T1/PRI, or SIP trunk), deploying virtual printer drivers on workstations, and running full integration testing with connected systems.

For most organizations evaluating fax infrastructure today, cloud deployment eliminates this complexity entirely — with no sacrifice in reliability, security, or compliance.

Fax Server vs. Virtual Fax Number

A virtual fax number is a component of a fax server solution — not a complete system on its own. A virtual DID gives you an inbound fax number that works over the internet; a fax server (or cloud fax service) is the platform that manages what happens with every fax sent to or from that number.

When you sign up for a cloud fax service like mFax Business, you get both: a virtual fax number (or porting of your existing number) and the full fax server infrastructure behind it.

Choosing Between On-Premises and Cloud

For most small to mid-size businesses, healthcare practices, and legal firms in 2026, cloud is the right default. On-premises deployments are justified when you have existing OpenText/RightFax infrastructure to leverage, deeply custom EHR integrations that require on-site connectors, or regulatory requirements that prohibit third-party data storage.

Send Faxes Without the Infrastructure

If your organization needs reliable, HIPAA-ready faxing without deploying and managing a fax server, mFax Business delivers the core capabilities at a fraction of the cost:

• Virtual fax numbers and number porting
• HIPAA compliance with BAA on every paid plan
• Team accounts and role-based access
• Audit trails and delivery tracking
• Fax from any device — desktop, browser, or mobile app

Plans start at about $9/mo — build your own plan by choosing the exact seats and pages you need, with no rigid fixed tiers. No hardware. No IT deployment. No busy signals.

Get started with mFax Business →