Why Does It Cost More to Store Data for Shorter Periods? (Retention Add-on)
You might notice that Postmark includes 45 days of message retention for free, but there’s a fee for choosing a shorter retention period (such as 7 or 14 days) with the Retention Add-on.
At first glance, that might seem counterintuitive — shouldn’t less data mean lower cost? Here’s why that’s not the case.
🧭 Understanding Retention Add-on Pricing
Data storage is only one of several factors that determine the cost of the Retention Add-on.
When you shorten retention, you’re not just reducing the amount of data stored — you’re also reducing the data available to Postmark’s compliance and abuse prevention systems.
Here’s what that means:
Less data = less visibility.
Our systems rely on message history to detect unusual or abusive sending patterns (for example, spam or phishing attempts).Higher risk for us as a provider.
With limited retention, there’s less historical data for us to analyze and verify sending behavior. That reduced visibility increases our compliance risk.
Because of this increased risk, there’s a small fee for enabling the Retention Add-on — even if you choose a shorter retention period.
📘 Example
| Retention period | Included in base plan? | Notes |
|---|---|---|
| 45 days | ✅ Yes | Default retention for all servers. |
| 7–14 days | ❌ Add-on required | Reduced visibility for compliance systems. |
| 90–365 days | ❌ Add-on required | Increased storage and compliance review costs. |
So while longer retention periods add costs due to storage and processing, shorter retention adds costs due to increased risk and the additional monitoring required to keep sending secure and compliant.
💬 In Short
Even though shorter retention means less data storage, it also means less data to detect and prevent abuse.
To maintain Postmark’s deliverability standards and compliance posture, we charge a small fee for enabling any custom retention period.
❓ FAQ
Can I choose a different retention period for each Message Stream?
Yes — retention is set at the stream level, so you can choose different retention periods for your Transactional and Broadcast streams based on your needs.
Does retention affect my webhooks?
No — webhooks are real-time and are sent immediately when events occur. Retention only affects how long message data is stored and visible in your Postmark account (UI and API).
Can I still access message metadata after data expires?
Once messages are deleted at the end of your retention window, all message data and metadata are permanently removed from Postmark. Webhook data you’ve already received will still exist in your own system.
Can I change my retention period later?
Yes — you can update your retention period anytime. Changes will apply going forward, and any existing data will be deleted once it exceeds the new retention period.
Does retention affect deliverability or sending speed?
No — retention only affects how long message history is stored. It does not impact message processing, delivery, or speed.
📚 Learn More
For full details about message retention and how the add-on works, visit:
👉 How does the Retention Add-on work?