| Price from | $1.35/mo | Free |
| Free plan | — | Yes |
| Free trial | Yes | — |
| Open source | — | — |
| Web | Yes | Yes |
| Windows | Yes | — |
| macOS | Yes | — |
| Linux | — | Yes |
| iOS | Yes | — |
| Android | Yes | — |
| API | Yes | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 3 | 1 |
| Spec score · Mail Server Software | 8.3 (#5) | 7.9 (#18) |
| Founded | 2001 | 2014 |
| Integrations | The product page describes Outlook Sync for syncing email, calendar, tasks, and notes with Outlook; the cloud API provides access to calendars, files, notes, contacts, tasks, and emails. | The documentation describes Nextcloud authentication through IMAP and calendar and address-book access through Radicale using WebDAV/CardDAV/CalDAV clients. |
| Product | IceWarp is an all-in-one collaboration platform combining email, messaging, video conferencing, file sharing, and real-time document collaboration in one interface. | Mailu is a free software mail server distributed as a set of Docker images. |
| Security | The pricing page lists antivirus and antispam with Core, while the site footer displays ISO 9001, ISO 27001, ISO 27017, ISO 27018, ISO 29119-1, SOC 2, and HIPAA compliance badges. | Listed security features include enforced TLS, DANE, MTA-STS, Let's Encrypt, outgoing DKIM, antivirus scanning, and blocking malicious attachments. |
| Support | The pricing page lists 24/7 support for cloud customers and offers Cloud Plus support with a 24/7 hotline and stated response targets. | 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. |
