Intelligent sending – optimizing the recipient database for email deliveries

Michal Michal Krejčí
5. September 2025

Email deliveries are still a key tool in marketing campaigns for maintaining contact with customers and potential clients. However, the success of such campaigns depends on the quality of the recipient database to which these emails are sent.

Best practice is to keep the recipients database up to date and not collect or import random recipients or recipients without consent under GDPR. It’s also important to regularly remove addresses from the database that are nonexistent, invalid, inactive, or that act as spam traps.

If your database isn’t cleaned, the bounce rate during deliveries can exceed an undesirable level, after which email servers will start to treat you as an unreliable sender and eventually block not only you but also the IP address from which the delivery is sent.

To help prevent similar unwanted situations in Boldem, we offer customers on the E-mailing plan the Smart Sending feature, which automatically evaluates database quality during deliveries and pauses sending if a set delivery threshold is exceeded, minimizing the risk of a high bounce rate.

How does Intelligent Sending work?

If the number of recipients in a delivery exceeds 1,000, emails will be sent automatically in two batches. This information will also be shown in the delivery details.

If the undelivered email rate for the first delivery is below 1%, the second batch will be sent to all recipients. Otherwise, the delivery will be paused and the user will receive information about the risks of sending and recommendations to address them.

What happens if the delivery failure rate exceeds 1%?

If the bounce rate exceeds 1% during sending, the following will occur:

  1. Suspension of deliveries: Deliveries will be suspended immediately to prevent further damage to the sender’s reputation.
  2. Notifying support and the customer: The customer will be notified of the situation along with the support department.
  3. Suggested solutions: Depending on the situation, the customer will be offered options. Typically there are two: either the customer cleans the database themselves, or they use one of the paid services that will help clean the database and improve recipient quality.

Smart sending for existing customers

Current customers can use the Intelligent Sending feature if they have the E-mailing plan activated. This plan provides advanced tools and features for better management of email campaigns and to ensure a higher-quality database.

Smart sending for new customers

For new customers, the rules for using the Smart Sending feature are as follows:

  1. Plan customers: Intelligent Sending is available only to customers subscribed to the E-mailing plan.
  2. Number of recipients: This restriction applies only to campaigns with more than 1,000 recipients.
  3. Time delay: When dispatching email campaigns, a delay will be set between individual batches, ranging from 2–4 hours.

Intelligent sending for new customers with a database of more than 50,000 recipients

Similar rules apply to new customers whose databases exceed 50,000 recipients, with a few specifications:

  1. Batching: Emails will be sent in batches of about 10,000 recipients.
  2. Time interval: Deliveries will be sent gradually, with a 2–4 hour interval.
  3. Delivery failure rate: If the delivery failure rate exceeds 1%, deliveries will be paused.
  4. Two deliveries: As with smaller databases, emails will be dispatched here in two batches.