Like all enterprise communication platforms, Firstup follows a series of required steps to deliver campaigns securely and at scale:

• Audience targeting: Identifying recipients based on your configured targeting criteria
• Personalization: Rendering individualized content for each recipient
• Email service provider coordination: Sending messages through industry-standard providers such as SendGrid (email-specific)
• Server acceptance management: Respecting the receiving email server’s message acceptance rate (email-specific)

These steps are essential for secure, personalized delivery. However, they can introduce slight delays compared to sending a single, non-personalized transactional communication (for example, a password reset with no rich content).

When a campaign is published, there may be a short delay before message sends begin if it includes rich media assets that require longer processing times, such as videos, attachments, polls, links, etc. This is expected and normal across all enterprise communication platforms, as each of these has to be rendered for everyone who qualifies for the campaign. As a result, the campaign will not begin sending messages until all assets have finished processing. This prevents users from encountering errors when attempting to open or download those assets. What this means in practice is that if you publish something immediately, it is expected that messages may not begin sending until a couple of minutes after clicking publish, depending on the types of assets or the number of assets used in the content. Similarly, if you schedule a campaign to be published at 9:00 am, it is expected that messages may not begin sending until 9:03 am, depending on the types of assets or the number of assets used in the content.

Campaign Delivery Flow

Step 1: Intake Users

During this step, the system qualifies the campaign audience into individual users by applying the filters you defined in the audience builder. The time required depends on the size of the audience, the filter logic complexity, and the current load on the system. This can range from a few seconds to a couple of minutes.

Step 2: Channel and Time Selection

Based on the campaign settings, the system evaluates each user to determine the appropriate delivery channel and time the campaign should be delivered. We then leverage these selections for the current campaign and store it to use in future campaigns to evaluate during smart channel selection.

Step 3: Rendering Communication Content (email-specific)

This step renders the email content by inserting personalized fields for each recipient. Campaigns that use Audience Block Targeting may take longer, as the system must determine which content variant(s) to generate for each user. This is expected and normal, as each of these has to be rendered for everyone who qualifies for the campaign before we begin sending to the qualified recipients.

Step 4: Sending the Communication (email-specific)

Once a channel and time are selected and the content is rendered, the rendered communication is then sent to the proper channel. When email is selected as a channel, the SendGrid delays we could see are generally related to customer configurations. SendGrid may return temporary errors such as “too many connections” or “rate limit exceeded.” When this occurs, messages are deferred and retried automatically. However, a large volume of deferred messages can reduce overall delivery throughput, as retries continue for up to 72 hours or until the message is successfully delivered or abandoned. If the number of deferrals reaches a critical level, retry traffic can saturate the sending pipeline, resulting in slower deliveries for other campaigns.

Email Delivery Speed

Email delivery speed is ultimately governed by your organization’s email infrastructure—not Firstup.

Most companies configure rate limits on their email servers (such as Microsoft or Google) to prevent system overload and maintain security. For example:

• If an email server accepts 100 messages per second
• And a campaign targets 50,000 recipients

The minimum delivery time is over 8 minutes, before accounting for personalization and processing overhead.

Industry Standard

Delivery times of up to 30 minutes for large email campaigns are common across enterprise communication platforms. This is a result of standard, secure email delivery practices and is not unique to Firstup. In practice, Firstup typically delivers much faster—for example, campaigns sent to 200,000 users are often delivered in approximately 15 minutes.