Postfix
Postfix: A flexible SMTP foundation for administrators building self-hosted mail infrastructure. Ranked #25 of 34 in Mail Server Software by our editors (6.7/10); pricing: Open source; best for flexible SMTP relay and delivery.
At a glance
- Editor score6.7 / 10
- PricingOpen source
- Best forFlexible SMTP relay and delivery
- Paid fromNone
- License modelOpen-source
- Facts checked21 Sep 2026
Where it wins
- SMTP services with queuing, scheduling, sending, receiving and relaying
- Virtual domains, virtual mailboxes, TLS, authentication and relay controls
- Filtering hooks and lookup backends for LDAP, SQL, SQLite and MongoDB
Where it doesn't
- Does not include webmail for end users
- Does not provide IMAP or POP3 access
- Requires separate software for a complete mailbox experience
Our verdict on Postfix
Postfix is open-source mail server software for system administrators operating Unix-like mail infrastructure. It functions as a mail transfer agent for sending, receiving and relaying email, with SMTP server and client support, message queuing, delivery scheduling, virtual-domain hosting and virtual mailboxes. Its platforms include Linux, macOS and self-hosted environments. Postfix fits teams that want to assemble and control their own mail stack rather than adopt a hosted mailbox or collaboration suite.
The strongest part of Postfix is its breadth as an SMTP foundation. TLS encryption, authentication, SMTP relay controls and access controls support common mail-routing requirements, while postscreen, DNSBL and greylisting support provide junk-mail controls. Content filtering and Milter integration add inspection and processing hooks. Lookup-table support extends to LDAP, SQL, SQLite, MongoDB and other backends, giving administrators several ways to connect mail handling with existing data stores. The published category specifications also identify antispam tools and high availability.
Postfix is deliberately narrower than an end-user email product. It does not provide webmail, IMAP or POP3 access, so mailbox access and browser-based email require separate components. That makes it a strong choice for administrators who need flexible SMTP relay, delivery control and self-hosted infrastructure, especially where virtual domains, filtering and database-backed lookups matter. Organizations seeking an all-in-one inbox, webmail interface or complete user-facing email suite should choose a product that includes those layers instead.
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Postfix pricing
Postfix fact sheet
| Free plan | Not verified |
|---|---|
| Paid from | None |
| License model | Open-source |
| Webmail interface | No |
| IMAP/POP3 access | No |
| Mobile sync | Not verified |
| Antispam tools | Yes |
| Mailbox limit | Not verified |
| High availability | Yes |
| Deployment | Self-hosted |
| Platforms | Linux, macOS |
| Support | Community, Docs |
| Built for | Small business, Mid-market, Enterprise (editorial estimate) |
| Pricing | Open source |
| Website | postfix.org |
| Facts checked | 21 Sep 2026 |
Alternatives to Postfix
- Microsoft Exchange OnlineA Microsoft-centric hosted mailbox service with Outlook, archiving, compliance, and migration tools.9.3
- Zimbra CollaborationA broad open-source suite for organizations that need email, collaboration, and deployment control.9.1
- IceWarpA broad hosted email suite with collaboration, migration tools, and self-hosted deployment.9.0
See all Postfix alternatives →
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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
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