Message Execution

When a campaign triggers, Trackly’s message execution system queues and delivers messages efficiently. This guide explains what happens behind the scenes.

Execution Flow

Campaign Triggers

At the scheduled time, the campaign begins processing

Audience Evaluation

The system queries matching contacts from your audiences

Message Queuing

Individual messages are created and queued

Delivery

The executor sends messages via your SMS provider

Status Tracking

Delivery status is tracked and updated

1. Campaign Trigger

When the scheduled time arrives:

The scheduler picks up the campaign
Validates configuration (sending list, audiences, creatives)
Begins audience evaluation

For recurring campaigns, a new execution starts each scheduled occurrence.

2. Audience Evaluation

The system queries all selected audiences:

Audience A: 5,000 contacts
Audience B: 3,000 contacts
Overlap: 500 contacts
-----
Total unique: 7,500 contacts

Filters applied:

Exclude unsubscribed contacts
Apply frequency capping (skip if sent recently)
Verify phone numbers are valid
Filter contacts based on timezone for TCPA compliance (contacts outside permissible sending hours are excluded)
Exclude contacts currently enrolled in an active Welcome Journey (always applied)

3. Message Queuing

For each contact:

Select the message variant (based on percentage split or ML selection)
Resolve any placeholders (, personalization)
Queue the message for delivery
Set the sendtime

Messages are bulk-inserted for efficiency.

Queue Priority

Messages are processed in order:

FIFO (first-in, first-out)
All messages from a campaign are queued together

4. Message Delivery

Queued messages are delivered in parallel, grouped by sending list, with each list’s rate limit applied. See Failure Handling for reasons a message might not be delivered.

Provider Integration

Each sending list has a provider configuration:

Provider	How Messages Are Sent
Infobip	REST API batch submission
Twilio	Messaging API
CM	Batch API

Rate Limiting

Your per-list rate limit applies across your whole account, not per campaign:

Configurable per-list rate limits (default 17,000 messages/minute)
Inter-batch delays to smooth throughput
Automatic backoff on provider errors

5. Status Tracking

After sending, message status is reported through two fields on each message:

Field	`null`	`true`	`false`
`submitted`	Not yet processed	Accepted by SMS provider	Rejected/failed to send
`delivered`	Delivery unknown	Delivered to handset	Delivery failed

Failure Handling

Messages that can’t be delivered are recorded with a failure reason (and a Discord alert, if configured):

STALE — Message older than 30 minutes (skipped)
BLOCKED_CONTENT — Message contains blocked words
CONTACT_BLOCKED — Contact is on the block list (unsubscribed)
RATE_LIMIT_TIMEOUT — Rate limit window expired
PROVIDER_ERROR — SMS provider returned an error
NO_RESPONSE — No response from provider

Permanent Failures

Messages that fail are logged with failed status. Common causes include:

Invalid phone number
Blocked/blacklisted number
Carrier rejection (spam)

Alerts

Alerts are sent via Discord when configured. This includes notifications for:

Delivery failures
Spam complaints
High error rates

See Discord Alerts to configure.

Retry Behavior

The system has built-in recovery mechanisms:

Billing backoff: Billing-blocked messages get 5-minute backoff with a 60-minute TTL before dead-letter
Interrupted sends: If a delivery attempt is interrupted, the message is automatically picked back up and retried, unless it has passed the 30-minute stale threshold

Delivery Webhooks

When delivery status updates are received, they update the message’s delivery status. The webhook payload looks like this:

{
  "id": "a1b2c3d4",
  "account": 12,
  "sendingList": 45,
  "messageCreative": 789,
  "fromNumber": "+15551234567",
  "toNumber": "+15559876543",
  "delivered": true,
  "sendType": "campaign",
  "filterBots": false,
  "length": 142,
  "timestamp": "2024-01-15T10:30:00Z"
}

See Webhook Events for details.

Execution Timeline

Typical timeline for a 10,000 message campaign:

Time	Event
0:00	Campaign triggers
0:01	Audience evaluated (10,000 contacts)
0:02	Messages queued
0:02 - 0:04	Messages sent
0:10+	Delivery confirmations arrive

Actual timing depends on:

Audience size
Queue depth
Provider capacity

Link Tracking

For messages with tracked links:

Original URLs are replaced with short links
Each short link is registered for click tracking
When clicked, the link service logs the click
User is redirected to the destination

See Link Tracking for details.

Monitoring Execution

Where to Track Progress

View campaign progress:

On the Schedules page, open the Logs tab to see Queued, Processed, and Skipped counts for each run
Go to Reports > Performance, open the Deliverability tab, and filter by Send Name to see Sent, Delivered, and Failed counts

Metrics

Metric	Description
Send Rate	Messages per second
Delivery Rate	% successfully delivered
Failure Rate	% that failed
Click Rate	% that clicked a link

Troubleshooting

Messages not sending

Check:

Is the campaign scheduled and not paused?
Is the sending list active?
Are provider credentials valid?
Is there a queue backlog?

High failure rate

Common causes:

Invalid phone numbers in list
Provider issues
Carrier blocks
Rate limiting exceeded

Review failed messages for error codes.

Slow delivery

Possible reasons:

Large queue from concurrent campaigns
Provider rate limits
Network issues

Create a support ticket from your dashboard (Support > New Ticket) if delivery is significantly delayed.

Common Pitfalls

Why are contacts being skipped?

Contacts may be skipped during campaign execution for several reasons:

In-workflow exclusion: A contact already enrolled in an active Welcome Journey is always skipped; this exclusion isn’t configurable.
Cooldown period: The contact received a message within the schedule’s Skip If Sent Within window (set in hours in the schedule’s Behavior section). Same-message and same-offer cooldowns are configured per account.
TCPA quiet hours: The send falls outside the contact’s local TCPA-compliant window (typically 8 AM–9 PM in the contact’s timezone).
Unsubscribed: The contact opted out via STOP keyword and is no longer active on the list.
Stale message: The message sat in the queue longer than 30 minutes and was dropped to prevent outdated content from being delivered.

Getting Started

AI Agents & MCP

Guides

Account & Team

Integrations

Resources

Execution Flow

1. Campaign Trigger

2. Audience Evaluation

3. Message Queuing

Queue Priority

4. Message Delivery

Provider Integration

Rate Limiting

5. Status Tracking

Failure Handling

Permanent Failures

Alerts

Retry Behavior

Delivery Webhooks

Execution Timeline

Link Tracking

Monitoring Execution

Where to Track Progress

Metrics

Troubleshooting

Common Pitfalls

Next Steps

Link Tracking

Discord Alerts

​Execution Flow

​1. Campaign Trigger

​2. Audience Evaluation

​3. Message Queuing

​Queue Priority

​4. Message Delivery

​Provider Integration

​Rate Limiting

​5. Status Tracking

​Failure Handling

​Permanent Failures

​Alerts

​Retry Behavior

​Delivery Webhooks

​Execution Timeline

​Link Tracking

​Monitoring Execution

​Where to Track Progress

​Metrics

​Troubleshooting

​Common Pitfalls

​Next Steps

Link Tracking

Discord Alerts

Execution Flow

1. Campaign Trigger

2. Audience Evaluation

3. Message Queuing

Queue Priority

4. Message Delivery

Provider Integration

Rate Limiting

5. Status Tracking

Failure Handling

Permanent Failures

Alerts

Retry Behavior

Delivery Webhooks

Execution Timeline

Link Tracking

Monitoring Execution

Where to Track Progress

Metrics

Troubleshooting

Common Pitfalls

Next Steps