When an email is sent through Sense, it goes through several validation and delivery stages before reaching the recipient's inbox. During this process, Sense and the email service provider work together to determine whether an email can be delivered successfully and to track its delivery status.

Understanding these stages can help you troubleshoot email delivery issues and interpret email engagement metrics.

Email Request Lifecycle

The following steps describe what happens after an email is triggered from a workflow.

Step 1: An email is triggered

An email is triggered from a workflow or another supported feature within the Sense platform.

Step 2: Sense validates the email request

Before sending the email, Sense performs several validation checks to ensure the request can be processed.

The following validations are performed:

• Verifies that the recipient email address is in a valid format.
• Verifies that the sender's domain is registered with Sense.
• Checks whether the email address was previously identified as an invalid address due to a hard bounce within the last six months.

If any of these validations fail, the email is Skipped and is not sent to the email service provider.

Step 3: The email request is sent for delivery

If the validation checks are successful, Sense forwards the email request to the email service provider for delivery.

At this stage, the email status is recorded as Sent.

Step 4: The email service provider validates the request

Before attempting delivery, the email service provider checks whether the recipient email address exists in one of its suppression lists.

If the email address is present in a suppression list, the email is not sent and the request is marked as Dropped.

Otherwise, the email service provider attempts delivery.

Step 5: Delivery outcome is recorded

Once delivery is attempted, the email is assigned one of several delivery events depending on the outcome.

Email Events

The following events may be recorded during the email lifecycle.

Sent

Indicates that Sense successfully forwarded the email request to the email service provider.

This status does not confirm that the email was delivered to the recipient.

Delivered

Indicates that the email was successfully delivered to the recipient's mail server.

A delivered email does not necessarily mean that it has been opened by the recipient.

Opened

Indicates that the recipient opened the email.

Clicked

Indicates that the recipient clicked a tracked link within the email.

Bounced

Indicates that the email could not be delivered.

There are two types of bounce events.

Hard Bounce

A hard bounce indicates a permanent delivery failure, such as an invalid email address.

When a hard bounce occurs:

• The email address is added to the email service provider's suppression list.
• Future emails are not sent to that email address from the same customer account.
• Sense also maintains a six-month record of invalid email addresses across customer accounts to help prevent repeated delivery attempts to known invalid addresses.

Soft Bounce

A soft bounce indicates a temporary delivery issue.

Examples include:

• Recipient mailbox is full.
• Temporary server issues.
• Temporary delivery delays.

The email service provider automatically retries delivery for up to 72 hours before recording the event as a soft bounce.

Unlike hard bounces, soft bounces do not permanently suppress future email delivery.

Spam Reported

Indicates that the recipient marked the email as spam.

When this occurs, the email address is added to a suppression list, and future emails are not sent to that recipient from the same customer account.

Unsubscribed

Indicates that the recipient unsubscribed from receiving emails.

The email address is added to a suppression list, and future marketing emails are not sent to that recipient.

Dropped

Indicates that the email service provider did not attempt delivery because the email address already existed in one of its suppression lists.

This can occur if the email address was previously:

• Hard bounced
• Reported as spam
• Unsubscribed

Skipped

Indicates that Sense did not send the email request because it failed one or more validation checks.

An email may be skipped for any of the following reasons:

• The recipient email address is invalid.
• The sender's domain is not registered with Sense.
• The recipient email address previously experienced a hard bounce due to an invalid address within the last six months.

Understanding Email Suppression

To help protect sender reputation and improve email deliverability, both Sense and the email service provider maintain safeguards that prevent repeated delivery attempts to invalid or blocked email addresses.

Email Service Provider Suppression

The email service provider automatically suppresses email addresses that have:

• Hard bounced
• Reported emails as spam
• Unsubscribed from email communications

Emails are not sent to addresses in these suppression lists.

Sense Validation

Sense maintains a six-month record of email addresses that previously experienced a hard bounce because they were identified as invalid.

Unlike the email service provider, which manages suppression at the customer account level, Sense performs this validation across customer accounts to reduce repeated delivery attempts to known invalid email addresses.

Additional Considerations

• You do not need to manually manage suppression lists to protect your sender reputation. The email service provider automatically maintains the required suppression lists.
• Soft bounce events do not permanently suppress an email address. Future email attempts are still allowed after the temporary delivery issue is resolved.
• If required, you can use Lists to exclude recipients who frequently experience soft bounce events from future campaigns.

Email Lifecycle Summary