| Price from | Free | $29.08/mo |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Web | Yes | Yes |
| Linux | Yes | Yes |
| API | Yes | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 1 | 3 |
| Spec score · Email Server Software | 7.9 (#13) | 8.0 (#10) |
| Spec score · Mail Server Software | 7.9 (#18) | 8.0 (#13) |
| Administration | Admin features include global administrators, announcements, per-domain delegation, and quotas. | The product includes web administration, a REST API, mailbox quotas, and per-mailbox settings. |
| Founded | 2014 | 2014 |
| Integrations | The documentation describes Nextcloud authentication through IMAP and calendar and address-book access through Radicale using WebDAV/CardDAV/CalDAV clients. | The documentation describes an Elasticsearch integration for PRO log viewing and names Uptime Kuma, Prometheus, and Grafana as external monitoring systems that can use its monitoring API. |
| Product | Mailu is a free software mail server distributed as a set of Docker images. | Poste.io is a self-hosted email server with web administration, webmail, spam protection, and mail server components in one Docker container. |
| Security | Listed security features include enforced TLS, DANE, MTA-STS, Let's Encrypt, outgoing DKIM, antivirus scanning, and blocking malicious attachments. | The feature page states that TLS is used on every protocol, passwords use salted SHA512, and SPF, DKIM, DMARC, and SRS are supported. |
| Support | The project directs simple questions to its Matrix room, complex questions to GitHub discussions, and bug reports to GitHub issues; it describes itself as mostly developed in contributors' free time. | The pricing page includes email support with PRO and PRO+, while FREE is marked as not including it. |