Workspace app
A browser-based, multi-mailbox webmail client built into Hollow, with proper credential security and a durable send queue.
Hollow Mail connects your IMAP and SMTP mailboxes and gives you one inbox inside Hollow: encrypted credentials, sandboxed rendering, and a send path that never silently drops a message.
Workspace app
Connect
Any IMAP and SMTP mailbox
Mail connects one or more IMAP and SMTP mailboxes by app password, and keeps everything searchable with its own full-text index, built on a dedicated database rather than borrowing storage from the rest of Hollow.
- Multi-provider, multi-mailbox, connected by app password
- Its own dedicated database, isolated from the rest of Hollow
- Full-text search across every connected mailbox
- Multiple providers
- Multiple mailboxes
- App-password auth
- Full-text search
Sync
A sync engine that does not lose mail
New mail arrives over IDLE on the inbox and polling on every other folder, with a jittered, self-healing reconnect and a safety-net scheduler behind it, so a stuck connection never quietly means missed mail.
- IDLE on the inbox, polling on other folders, backed by a safety-net scheduler
- A safety-net scheduler catches anything a stuck connection misses
- Bodies and attachments are cached, so most repeat reads never hit IMAP again
- IDLE on the inbox
- Polling everywhere else
- Self-healing reconnects
- A safety-net scheduler
Security
Encrypted, sandboxed, and rate-limited
Mailbox credentials are encrypted at rest, HTML mail renders in a sandboxed iframe on its own subdomain with strict security headers, and every image and link is checked so it cannot reach an internal service before it loads. Sending goes through a durable outbox queue that retries and never silently drops a message.
- Per-mailbox credentials encrypted with a per-user derived key
- HTML mail sanitised and rendered in a sandboxed iframe
- A durable outbox queue retries transient failures, dead-letters permanent ones, and flags anything stuck for review
- Encrypted mailbox credentials
- Sandboxed rendering
- Blocks internal requests
- A durable send queue
What’s inside
A proper inbox, properly built
- 01
Multi-mailbox inbox
Connect multiple IMAP and SMTP mailboxes by app password.
- 02
Full-text search
Search across every connected mailbox from one bar.
- 03
Reliable sync
IDLE and polling hybrid with a self-healing, safety-net scheduler.
- 04
Durable sending
A retrying outbox queue that never silently drops a message.
- 05
Sandboxed rendering
HTML mail renders in a sandboxed iframe with strict security headers.
- 06
Draft autosave
Compose with attachments, drag-and-drop, and autosaved drafts.
One inbox, properly secured
Mail is part of Hollow, invite only while we open access in stages.