SendThread
Built for High-Deliverability Sequences & Outreach

Build the sequence. Let email run itself.

SendThread connects directly to your Gmail or Google Workspace account to schedule and send multi-step email workflows with relative timing, server-side background execution, and complete state tracking.

Native Gmail API (gmail.send)
100% Server-Side Execution
AES-256-GCM Token Encryption
Idempotent Job Engine
Workspace: Delhi Startup Outreach
Active (4 Steps)

25 Contacts Enrolled • Server-side automated dispatch

Gmail: rahul@sendthread.io
1
Quick introduction
Sent immediately upon contact enrollment
Sent (25/25)
2
Following up on intro
Delay: 3 days after Step 1
Scheduled (24)
3
A useful idea for your team
Delay: 5 days after Step 2
Queued
4
Closing the loop
Delay: 7 days after Step 3
Queued

Reliable 4-Step Lifecycle

How SendThread Executes Your Sequences

No complicated marketing automation bloat. Just direct, reliable email sequencing with rock-solid server-side delivery.

1. Connect Gmail

Authorize your Google Workspace or Gmail account via OAuth with minimal gmail.send scope.

2. Add Contacts

Organize outreach by workspaces. Contacts are syntax-validated and protected against duplicate active enrollments.

3. Define Delays

Build your sequence using relative delays (e.g. 3 days after Step 1). The engine computes exact UTC execution timestamps.

4. Run Autonomously

Server-side background workers process jobs on schedule. Close your laptop, shut down your browser — delivery continues.

Engineered for Production

Built on Modern Architecture

Designed from the ground up for strict data isolation, zero duplicate sends, and transparent execution state.

Relative Scheduling Engine

Users think in relative time (hours or days between steps). The engine normalizes delays into immutable UTC timestamps for each contact.

Idempotent Job Processing

Every email send is protected by strict state transitions. A retry will never send the same email twice to the same recipient.

AES-256-GCM Token Security

Google OAuth refresh tokens are encrypted at rest using server-side AES-256-GCM. Private secrets never touch client JavaScript.

Pause, Resume & Safety Controls

Pause an entire workspace or a single contact instantly. Already sent emails remain in logs while future scheduled jobs are held.

Supabase Row Level Security

Multi-tenant isolation at the database layer. Users can never view or manipulate another user's workspaces, contacts, or logs.

Dynamic Contact Enrollment

Add new contacts to an already running sequence at any time without disturbing in-progress timelines of existing recipients.

Relative vs. Calendar Scheduling

No rigid dates. Configure human delays that scale.

Traditional tools force you to pick arbitrary calendar dates for email blasts. SendThread operates on relative step offsets:

Independent timelines: Contact A enrolled on Monday gets follow-up on Thursday; Contact B enrolled on Wednesday gets follow-up on Saturday.
Universal UTC synchronization: Eliminates DST confusion and cross-timezone dispatch bugs.
Anti-Spam Pacing: Prevents overwhelming Gmail sending quotas by spacing out deliveries naturally.
// Relative Delay Calculation Traceengine: operational
// Sequence Step Definitions
Step 1: delay = 0 minutes  (Initial Introduction)
Step 2: delay = 3 days     (Follow-up)
Step 3: delay = 5 days     (Value proposition)
Step 4: delay = 7 days     (Closing the loop)

// Contact Enrolls: 2026-08-23T10:00:00.000Z
Step 1 Execution -> 2026-08-23 10:00:00 UTC [SENT]
Step 2 Execution -> 2026-08-26 10:00:00 UTC [SCHEDULED]
Step 3 Execution -> 2026-08-31 10:00:00 UTC [PENDING]
Step 4 Execution -> 2026-09-07 10:00:00 UTC [PENDING]

Security By Design

Your Inbox, Protected

SendThread strictly minimizes requested Google scopes and guarantees server-isolated credential protection.

Minimal Gmail Scopes

Only what is necessary

We only request the narrowest possible permission: https://www.googleapis.com/auth/gmail.send. SendThread does not read personal emails or access your drive.

Zero Client-Side Credentials

Defense in depth

OAuth access and refresh tokens are encrypted on the server before storage in Supabase PostgreSQL. Service keys are safeguarded by Next.js server-only boundaries.

Ready to automate your email follow-ups?

Connect your Gmail account, build your relative sequence, and let the server-side scheduler do the heavy lifting.