SES pricing: what to model (send volume + payload size)

SES pricing models are usually linear: emails sent × effective $ per 1,000 emails. The difficult part is getting the volume right (and not ignoring incident multipliers). If you send large templates or attachments, add a payload-size assumption as a separate line item so you can reason about trade-offs.

Quick SES pricing inputs

• Emails sent: total send volume per month.
• Payload size: avg KB per email for transfer costs.
• Delivery path: internet egress vs in-region recipients.

What to include in your estimate

• Emails/month: transactional + marketing + notifications
• Peak/incident scenario: retries, duplicates, and alert storms
• Average email size (optional): templates, images, and attachments
• Dedicated IP / add-ons (if used): treat as fixed baseline line items

Tool: AWS SES cost calculator

Step 1: estimate email volume (separate by intent)

• Transactional: password reset, receipts, signup confirmation, security alerts
• Product notifications: digests, alerts, workflow messages
• Marketing: campaigns, newsletters, onboarding sequences

Workflow: estimate email volume per month

Step 2: price baseline sends

Baseline monthly send cost is typically:

• Baseline cost ≈ emails/month × $/1,000 emails
• Keep separate assumptions for transactional vs marketing if they have different variability (marketing can be bursty).

Step 3: add the incident multipliers (the common budget miss)

• Retry loops: timeouts and downstream failures can cause repeated sends.
• Duplicate notification logic: one user action triggers multiple sends accidentally.
• Alert storms: incidents trigger high-frequency alerts to large recipient sets.

A simple approach: add a “duplicates/retries factor” (for example +5% baseline, +50% in peak month) and validate after you deploy.

Step 4: include payload size only if it’s meaningful

Many teams can ignore payload size for budgeting. Include it when you send large templates or attachments, or when you route email content through a path with measurable data-transfer billing.

• Estimate average email size (kB) for transactional vs marketing templates.
• Prefer links to downloads instead of attachments when feasible.
• Use the same unit conventions (MB vs MiB) when you convert sizes.

Helper: units converter

How to validate after the first month

• Compare actual sends/day to your baseline and identify campaign vs incident spikes.
• Track retry/duplicate rate (resends and idempotency failures).
• Validate deliverability (bounces/complaints) when you change templates or volume.

Related guides

Sources

• AWS SES pricing
• SES sending concepts (deliverability and sending patterns)

Related guides

Related calculators

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