This page is mainly to compare all active and mature Open Source (thus self-hostable) webmail solutions that you can install and manage email from any server with standard email protocols (IMAP, SMTP, JMAP). The assumption is that you already have at least one mail server (and often more than one) and you just want to install a webmail, and perhaps replace a desktop email solution like Thunderbird.
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Here are the main active and mature Open Source standalone webmail options:
Special cases:
Some related solutions are added because they have a close connection with one of the solutions above
| Roundcube | Kolab | SnappyMail (RainLoop fork) | Nextcloud | Cypht | Tiki Wiki CMS Groupware | Virtualmin | |
| Type | Webmail in PHP | Full mail server stack (server and webmail) | Webmail in PHP and Node.JS | Multi-feature system which offers plugins/modules, and some of those are webmail clients | Pluggable Webmail in PHP with aggregator mindset | Multi-feature system which offers all the functionality in one app (bundles Cypht Webmail) | Admin panel for shared hosting which includes mail accounts and its own webmail (You can also install Cypht, Roundcube, etc.) |
| Mail server | NoneIt's an email client, and you can connect to any mail server via standard protocols (IMAP, etc.) | Cyrus IMAP | NoneIt's an email client, and you can connect to any mail server via standard protocols (IMAP, etc.) | NoneIt's an email client, and you can connect to any mail server via standard protocols (IMAP, etc.) | NoneIt's an email client, and you can connect to any mail server via standard protocols (IMAP, etc.) | NoneIt's an email client, and you can connect to any mail server via standard protocols (IMAP, etc.) | Dovecot |
| License | GPLv3+ with exceptions for skins and plugins | Various components use various Open Source licenses | AGPLv3 | AGPLv3 | LGPL v2.1 | LGPL v2.1 | GPL |
| Available via Packagist.org | No | No | No | No | Yes | No | No |
| Available via Docker | yes | This image does not provide persistence, and is intended for testing and demo purposes | ? | Yes | Yes | Yes | No |
| Uses Bootstrap | Yes | yes, via Roundcube | Yes? | No | Yes | Yes | Yes |
| External authentication | ? | ? | ? | Yes, via Nextcloud (social logins, oidc, ldap, others) | API, LDAP and others | LDAP (Active Directory), OpenID Connect, SAML, Hybridauth Social Sign On Library, CAS, Shibboleth, etc. | ? |
| Webmail client | Yes | Yes, via Roundcube | Yes | Nextcloud mail | Yes | Yes, via Cypht | Usermin Webmail. |
| How does it deal with mail accounts? | Only 1 external account at a time | Only own accounts? | Multiple external accounts but messages are not in a unified view | Multiple external accounts in a unified view | Multiple external accounts in one view | Multiple external accounts (via Cypht) | Only own accounts? |
| Possible to copy/move an email between IMAP accounts? | No | No | No | ? | Yes | Yes, via Cypht | ? |
| Manage Sieve | via a plugin | Yes? | yes but no GUI in demo | Yes, but very basic | Yes, with a GUI A modern Sieve library in PHP was developer for this | Via Cypht, and available even if server doesn't support Sieve | No (uses Procmail instead) |
| Mail: Search throughout all folders | Yes | Yes, via Roundcube | Yes | Yes | assigned to a developer | Missing (via Cypht) | ? |
| JMAP support | No | No | No | No | Yes, in version 2+ | Yes, via Cypht | No. See related discussion about JMAP and Virtualmin |
| Exchange Web Services (EWS) support | No | No | No | No | In development | In development, via Cypht | No |
| Calendar invitations by email | ? | Yes | ? | Yes? | No | Yes | No |
| Calendar | ? | Yes | ? | Nextcloud calendar | very basic | Tiki Calendar | No? |
| CalDAV | ? | Yes | ? | yes | No | yes | ? |
| Contacts | Yes | Yes, via Roundcube | Yes | Yes | Yes | Tiki Contacts with interop with Cypht contacts | Yes |
| CardDAV | ? | Yes | ? | yes | read-only | yes | ? |
Should be analyzed:
Not included (yet), and why?
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