Open WebMail
What Open WebMail is
Open WebMail is a free, open-source webmail system for Linux, self-hosted installations, and web access. It is designed for very large mail folders while using memory efficiently, and includes tools intended to help users move from Microsoft Outlook. Mail functions include full-content search, drafts, read confirmations, spell checking, POP3, and filters that move or copy matching messages into target folders. A unified inbox, vCard-compliant address book, multiple global address books, and a calendar with reminders and notifications are included, along with webdisk support. Administrators can configure authentication modules, PAM, SMTP relaying, virtual hosting, user aliases, and per-user capabilities. SpamAssassin checking and ClamAV virus checking are supported through external programs that administrators must install and configure. Installation requires Apache with CGI enabled and Perl 5.005 or later, with guidance for Linux, FreeBSD, and other Unix systems. The project notes limited support for global filter rules and calendars, including manual file copying.
Who it suits
Open WebMail suits administrators seeking a free, self-hosted webmail system for large mail folders. It is also relevant to organizations migrating users from Outlook and managing Unix-based servers.
What it does well
- Designed for very large mail folders
- Full-content search, POP3, filters, and unified inbox
- vCard address book and calendar reminders
- Multiple authentication and virtual-hosting options
- Free, open-source project
What to know first
- Requires Apache CGI and Perl 5.005 or later
- Spam and virus tools need separate installations
- Global filters and calendars have limited support
- Administrator configuration is required
Verdict
Open WebMail provides broad mail, contact, calendar, and administration features without a listed cost. Its server requirements and limited calendar/filter support make deployment and maintenance important considerations.
Facts from Open WebMail's own pages
- Address book
- The address book is vCard compliant, and the system supports multiple global address books. · openwebmail.org, 12 Oct 2026
- App coverage
- web · openwebmail.org, 24 Sept 2026
- Calendar and webdisk
- The feature list includes a calendar with reminders and notifications, plus webdisk support. · openwebmail.org, 12 Oct 2026
- Calendar tools
- Yes · openwebmail.org, 24 Sept 2026
- Contacts and calendar
- It includes a vCard-compliant address book and a calendar with reminders and notifications. · openwebmail.org, 12 Oct 2026
- Deployment
- The project download instructions describe installing a release archive and required packages, and the project offers Linux package directories for Rocky Linux, RHEL, Ubuntu, CentOS, and Debian. · openwebmail.org, 12 Oct 2026
- Free plan
- Yes · openwebmail.org, 24 Sept 2026
- Large mail folders
- It is designed to manage very large mail folder files in a memory efficient way. · openwebmail.org, 12 Oct 2026
- License
- The project site links a GNU General Public License Version 2 license document. · openwebmail.org, 12 Oct 2026
- Limitations
- The readme says support for global filter rules and calendars is very limited and requires administrators to copy files manually. · openwebmail.org, 12 Oct 2026
- Mail features
- The documented user features include full content search, draft folders, read confirmations, spell checking, POP3, and mail filters. · openwebmail.org, 12 Oct 2026
- Notable configuration limit
- Spam and virus checks rely on external programs and must be enabled and configured by the system administrator. · openwebmail.org, 12 Oct 2026
- Outlook migration
- It includes features intended to help users switch smoothly from Microsoft Outlook. · openwebmail.org, 12 Oct 2026
- Performance
- The FAQ recommends SpeedyCGI and says Open WebMail can run 5 to 10 times faster with it. · openwebmail.org, 12 Oct 2026
- POP3 and filtering
- It supports POP3 and mail filters that move or copy matching inbox messages to target folders. · openwebmail.org, 12 Oct 2026
- Product
- Open WebMail is a webmail system designed to handle very large mail folders with low memory use and help users migrate from Microsoft Outlook. · openwebmail.org, 12 Oct 2026
- Project contact
- The project homepage lists Thomas Chung as the contact for questions about the page. · openwebmail.org, 12 Oct 2026
- Requirements
- The readme lists Apache with CGI enabled and Perl 5.005 or above as requirements. · openwebmail.org, 12 Oct 2026
- Spam and antivirus
- SpamAssassin spam checking and ClamAV virus checking are supported through external programs. · openwebmail.org, 12 Oct 2026
- Spam and virus tools
- It supports spam checking through SpamAssassin and virus checking through ClamAV, which must be installed separately. · openwebmail.org, 12 Oct 2026
- Support
- The project says it is an open-source effort supported by volunteer contributors and solicits donations for hosting and coordination. · openwebmail.org, 12 Oct 2026
- System administration
- System features include various authentication modules, PAM support, virtual hosting, user aliases, and per-user capability configuration. · openwebmail.org, 12 Oct 2026
- System features
- Documented system capabilities include multiple authentication modules, PAM, SMTP relaying, virtual hosting, and per-user capability settings. · openwebmail.org, 12 Oct 2026
Where Open WebMail stands on Freedom251
- Email clients#99 of 142