Best Mail Servers in 2026

An open source mailserver suite.

Key mailcow features:

Comprehensive Feature Set Open Source Docker-based Deployment Active Community and Support

Open Source

Business email without the bloat.

Visit website paid $1 / Monthly ($1/mo per mailbox) Sponsored

Self-hosted email security gateway and mail server, open source.

Key Hermes SEG features:

Gateway, mail server or hybrid: Spam, virus and malware filtering Encryption built in Full archiving with self-service recovery

Open Source freemium $29 / Monthly (Pro Edition 1 Server)

Deploy your own unlimited SMTP server in one bash command. Self-hosted, secure, and built for email marketing.

Key SMTP-Builder.com features:

Unlimited SMTP Server Trusted Email Sender High Sending Score Full Mail Server

paid $3.99 (1 SMTP Builder Credits)

Modernize your mail server.

Key Stalwart Labs features:

Innovative Technology Experienced Team Comprehensive Solutions

Open Source free

ZEST provides simple, secure, fully manages servers with email, VPN and file transfer servers.

Key z3.st features:

Privacy Focused Budget Email Server File Transfer Fast VPN

paid Free Trial $10.9 / Monthly (Essential Server)

Mail-in-a-Box provides webmail and an IMAP/SMTP server for use with mobile devices and desktop mail software and also includes contacts and calendar synchronization.

Key Mail-in-a-box features:

Ease of Setup Full Control Cost-effective Open Source

Open Source

Protect mail server against spam, viruses and malware with Proxmox Mail Gateway security for businesses, government, education and non-profit organizations.

Key Proxmox Mail Gateway features:

Open Source Cost-Effective High-Quality Spam Detection Comprehensive Security

Prevent targeted email-borne attacks with Mimecast Secure Email Gateway for cloud-based anti-virus and anti-spam protection.

Key Mimecast Secure Email Gateway features:

Advanced Threat Protection Comprehensive Email Security User-Friendly Management Console Seamless Integration

Postfix is a mail transfer agent (MTA) that routes and delivers electronic mail.

Key Postfix features:

Security Performance Compatibility Reliability

Google's encompassing suite of cloud-based business apps.

Key Google Workspace features:

Integrations Collaboration Cloud Storage Security

Learn about Proofpoint's email security solutions that protect organizations against threats such as email fraud, phishing, spam, bulk email, and viruses.

Key Proofpoint Email Security and Protection features:

Advanced Threat Protection Threat Intelligence URL and Attachment Defense Data Loss Prevention (DLP)

Secure email with absolutely no compromises. Get your free encrypted email account today.

Key ProtonMail features:

End-to-End Encryption Zero Access to User Data Swiss Privacy Laws Open Source

freemium €5 / Monthly (user - 5 GB)

Scale your business email & marketing messages with Amazon Simple Email Service (SES), a cost-effective and reliable cloud email service. Sign up today.

Key Amazon SES features:

Cost-Effective Scalable High Deliverability Integration with AWS Services

Open Source