Self-hosted email server for 2026
single binary, CalDAV
Details
- External ID
- 46481354
- Source
- HN
- Company
- —
- Product
- Self-hosted email server for 2026
- Website domain
- github.com
- Launched
- Jan. 3, 2026
- Cohort
- —
- Upvotes
- 7
- Upvotes percentile
- 0.3544137022397892
- Tags
- —
- Fetched at
- Sept. 7, 2026, 9:25 p.m.
- Updated at
- Sept. 7, 2026, 9:25 p.m.
Description
Built this after getting frustrated with the paying to a google for email. Now running it for 1 months in production.What it does: - Full SMTP server (inbound/outbound, DKIM signing, SPF/DMARC checking) - IMAP with IDLE support - CalDAV/CardDAV (replace Google Calendar/Contacts) - Web admin panel with Prometheus metrics - Greylisting for spam prevention - Auto-discovery (mail clients configure themselves) - Audit logging for complianceWhat it doesn't do: - Webmail (use Roundcube, etc.) - ML-based spam filtering (greylisting + basic heuristics only) - Clustering/HA
Enrichment
- Theme
- email infrastructure and inbox utilities
- Vertical
- Horizontal
- Function
- Dev tools
- Audience
- Developer
- AI stance
- Not AI
- Project type
- Hobby / open-source project
- Normalized one-liner
- self-hosted email server with caldav support
- Manually corrected
- False
Could you build this?
No Writing a compliant, secure, single-binary email and CalDAV server implementing full SMTP, DKIM/SPF/DMARC, and IMAP IDLE requires deep protocol implementation and email deliverability expertise that vibe coding cannot safely replicate.
What it would actually take: The architecture requires a systems language (Go or Rust) implementing low-level RFCs for SMTP (RFC 5321), IMAP4rev1 (RFC 3501) with IDLE, MIME parsing, cryptographic signing (DKIM), and WebDAV/CalDAV/CardDAV specs (RFC 4791, 6352). Beyond protocol engineering, real-world deployment requires strict memory safety, robust queue persistence, TLS handling, spam filtering (Rspamd integration), and navigating IP warming and global deliverability blacklists.
Discussion
5 comments analyzed.
Competitors mentioned: Maddy, Mox, Stalwart, Google Workspace, Postgres/MySQL
Concerns raised: Unclear differentiation from established mail server alternatives, Server binds to all interfaces by default without configuration option
Feature requests: bind_address config option for multi-homed machines, API for transactional emails, Webhooks support
Competitors
Other products that read as similar to this one — 77 launches clear the similarity bar, closest 8 shown.
Attention rank: #45 of 78 (itself plus its competitors, highest first — normalized so YC and Product Hunt are compared fairly).
Launched 14 days after the earliest competitor.
- Posthorn, self-hosted mail gateway · hn · 2026-05-27 · 83 upvotes · similarity 0.49
- Mail client optimized for self-hosted email across multiple domains · hn · 2026-08-20 · 5 upvotes · similarity 0.47
- imyemail · ph · 2026-09-12 · 1 upvotes · similarity 0.44
- MailCraft · ph · 2026-09-26 · 2 upvotes · similarity 0.44
- OfficialMail · ph · 2026-09-22 · 3 upvotes · similarity 0.42
- VaultSandbox · hn · 2026-01-06 · 58 upvotes · similarity 0.41
- xMailman · ph · 2026-09-11 · 2 upvotes · similarity 0.41
- jev-gmail-ai-spam-filter-and-labeling · github · 2026-09-19 · 16 upvotes · similarity 0.41
Other launches for this product
- No other launches for this product.
Same idea, different domain
Nobody's really built a dev tools tool for Sales yet.