Sendora is a local-first desktop application for businesses, agencies and teams that need control over the complete email workflow—from importing and cleaning audiences to content, SMTP infrastructure, delivery queues, analytics and compliance. Its Rust engine and SQLite workspace run locally, keeping operational data under your control while every campaign can be monitored in real time.
More than another email sender
Most email products focus on the editor and the Send button. Sendora is designed around the difficult part: preparing data correctly, controlling sending infrastructure, managing delivery for every recipient, recovering from failures and understanding what actually happened after a message left the application.
Instead of connecting several services and scripts, you get one workspace where audiences, campaigns, SMTP accounts, content, queue jobs, delivery events, suppressions and reports are related to one another. Sendora is suited to newsletters, operational communications, permission-based commercial campaigns and professional workflows where control and traceability matter.
Clean, eligible audiences that are ready for campaigns
The Audience Engine imports CSV and TXT as bounded streams and processes XLSX, XLS, XLSB and ODS workbooks in controlled database batches. Header detection, editable column mapping and sample previews let you correct the structure before data is committed.
Addresses are normalized, validated and deduplicated per list. Consent is explicit, and contacts without consent remain ineligible for sending. Every import performs a mandatory global-suppression check, retains its import history and reports errors at row level. Persistent lists and smart segment definitions make it possible to organize large audiences without losing origin, eligibility or audit context.
Campaigns controlled by a real operational engine
Campaign creation follows a clear flow: setup, audience, sender pool, content and delivery. A campaign can start immediately or be scheduled in UTC, then paused, resumed, stopped or retried for failed recipients. Draft, Scheduled, Running, Paused, Completed, Failed and Stopped are persistent transactional states rather than temporary labels in a browser screen.
Before a message is sent, Sendora rechecks eligibility, consent and suppressions. Every campaign receives an immutable snapshot of the selected content version, so later reports always correspond to the message that was actually used—even when the original template changes after launch.
Professional SMTP infrastructure and intelligent sender pools
Sendora manages individual SMTP accounts and advanced bulk imports, with authentication, TLS, STARTTLS and optional relay-delivery tests. Accounts can be organized into pools with weighted rotation, per-minute limits, daily limits and capacity rules.
Background health checks record latency and failure history. After repeated failures, a circuit breaker temporarily removes a sender from rotation and returns it after a cooldown. The Rust queue reserves sender capacity before every attempt, reducing the chance that concurrent workers exceed the same provider limit.
A persistent queue for every recipient
Every recipient receives a persistent SQLite queue job. Atomic claims prevent two workers from processing the same job, while campaign and provider limits are enforced before each attempt. Temporary errors use exponential retry backoff capped at six hours, and capacity waits do not waste retry attempts.
If the application or computer closes unexpectedly, interrupted jobs are recovered on startup and returned to the retry flow. Progress is not silently discarded, and stable message identifiers help downstream systems associate multiple attempts with the same delivery.
Content Studio for controlled, verifiable messages
Content Studio includes persistent templates, subjects, variables, fallbacks, local assets and immutable version history. Required variables can block generation when a value is missing, and inserted values are resolved with HTML escaping. Recipient-seeded preview lets you inspect a genuinely personalized message before launch.
HTML preflight checks for risky or problematic elements such as scripts, forms, external stylesheets, a missing viewport, a missing unsubscribe path and excessive message size. Sendora builds HTML and plain-text MIME alternatives and can run a real delivery test through a saved SMTP account—the desktop test is not a visual simulation.
Deliverability, compliance and analytics from real events
Sendora stores accepted, deferred, failed, bounced, unsubscribed and complaint events. Provider webhooks are HMAC-SHA256 signed and processed idempotently. Bounce inboxes can be synchronized over TLS IMAP, while MIME and DSN messages are correlated with queue jobs and classified as hard or soft bounces.
Hard bounces, complaints and unsubscribes can create automatic suppressions according to your saved rules. Every queue job receives an unsubscribe token, and outgoing messages can include both the individual link and standard List-Unsubscribe and List-Unsubscribe-Post headers. Live DNS checks for SPF, DKIM and DMARC retain history and calculate a domain-readiness score.
Live dashboards aggregate campaign performance, timelines, recipient domains and sender results directly from SQLite. Delivery events, campaign summaries, suppressions and audit logs can be exported to CSV, while retention periods remain configurable.
Local-first: your engine and operational data remain under your control
Sendora is built as a Tauri desktop application with a Rust backend and SQLite in WAL mode. Audiences, content, campaigns, queue state, analytics, notifications, settings and configured infrastructure are retained in the local Sendora workspace. A copy made after closing the application can serve as a portable backup of the complete workspace.
The architecture does not require uploading lists and content to a cloud dashboard for processing. Rust-to-interface events update progress without constant polling, while native notifications, quiet hours, per-category rules and Light, Dark and System themes create a modern desktop experience. Because this is a local operational workspace, Windows account access and backup media should be protected as carefully as the SMTP infrastructure itself.
Why Sendora stands apart
• One complete operational flow: audience, content, senders, queue, delivery, compliance and analytics work with the same persistent records.
• Recipient-level control: every address has state, retries, events and audit history—not only a campaign-level percentage.
• A local Rust core: critical operations run in a native backend with SQLite transactions and startup recovery.
• Transparent SMTP infrastructure: limits, rotation, health, latency and failure history are visible for every sender.
• Compliance before and after delivery: consent, suppressions, unsubscribe, bounces, complaints and SPF/DKIM/DMARC checks are part of the workflow rather than afterthoughts.
• No false promises: Sendora provides the tools for healthier infrastructure and better deliverability, but it does not claim to guarantee inbox placement or bypass provider policies.
• Ownership and portability: the workspace can be managed and backed up locally instead of being fragmented across unrelated services.
Who Sendora is for
Sendora is built for marketing teams, agencies, online stores, SaaS products, publishers, newsletter operators and organizations that send legitimate communications to permission-based audiences. It is the right step when you have outgrown a basic newsletter editor and need genuine visibility into data, infrastructure and every delivery.
Sendora turns email sending from an opaque action into a controlled, measurable and recoverable operation. Build cleaner audiences, deliver responsibly and understand exactly what happens after you press Send.
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