Horde IMP
The facts below are what the maker publishes about Horde IMP, checked and dated. Our editors have not written about it yet.
Plans and prices
From Horde IMP's own pricing page, checked 12 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| IMP | Free | Open source webmail application; requires a Horde installation and an IMAP or POP3 server |
The facts
Each one read from Horde IMP's own pages, with the date it was checked.
Where it runs
- App coverage
- webchecked 23 Sep 2026
- Browser views
- It provides dynamic, mobile, basic, and minimal text-only interfaces for different browsers and devices.checked 12 Oct 2026
What it does
- Calendar tools
- Yeschecked 23 Sep 2026
- Composition
- Features include HTML composition with a cross-browser WYSIWYG editor, HTML signatures, and drag-and-drop attachment support.checked 12 Oct 2026
- Encryption
- IMP supports S/MIME and PGP-based encryption and signatures; OpenSSL is required for S/MIME and for TLS or SSL connections to mail servers.checked 12 Oct 2026
- Installation
- The guide recommends installation through PEAR and also documents installation from Git for development code or unreleased fixes.checked 12 Oct 2026
- Integrations
- The feature list names integration with Horde's Ingo email filtering, Turba address book, and Kronolith calendar applications.checked 12 Oct 2026
- Mailbox management
- It supports IMAP folders, shared-folder ACL management, folder subscriptions, multiple identities, and mailbox quotas.checked 12 Oct 2026
- Mail tools
- Features include flexible message search, address autocompletion, spell checking, thread view, mailbox previews, and forwarding multiple messages at once.checked 12 Oct 2026
- Open source
- The project describes IMP as OSI Certified Open Source Software.checked 12 Oct 2026
- POP3 limit
- With POP3, on-demand filtering, searching, and sorting are disabled, and the POP server must support UIDL.checked 12 Oct 2026
- Prerequisites
- IMP requires a working Horde installation, PHP file-upload support, at least one IMAP or POP3 server, and Sendmail or an SMTP server.checked 12 Oct 2026
- Purpose
- IMP is a PHP webmail client that provides browser access to IMAP and POP3 accounts.checked 12 Oct 2026
- Security configuration
- The installation guide recommends SSL for browser-to-web-server traffic and TLS or a private network for web-server-to-mail-server traffic; TLS is the default mail-server connection configuration described there.checked 12 Oct 2026
- Support
- The project points users to its FAQ, application mailing lists, and occasional IRC support from Horde developers, contributors, and users.checked 12 Oct 2026
Money
- Free plan
- Yeschecked 23 Sep 2026
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