Know what your sending service offers
These are product limits and metric definitions, not delivery guarantees. Monthly volume, submission speed, and arrival in a subscriber’s inbox are different measures.
- Subscribers and sends
- Subscribers are unique subscribed email addresses across your owned workspaces. Sending four newsletters to 10,000 subscribers produces 40,000 sends. Duplicate addresses count once; unsubscribed, bounced and complained contacts do not count toward a subscriber band.
- Unlimited sends
- New subscriber-based plans have no monthly send allowance. This does not mean unlimited sending speed, guaranteed inbox placement or permission to send unsolicited email. Existing send-based subscriptions retain their purchased allowance.
- Subscriber price
- From $15/month for up to 1,000 active subscribers. Published bands run through 500,000 subscribers, with Custom pricing above that. Annual billing saves 10%. No automatic overage charges.
- Import batch
- Up to 1,000 contact records per server batch. Larger files are split into batches by the import workflow.
- Campaign content
- Up to 90 KB of stored HTML before the delivery footer is added. Keep images externally hosted.
- Sending speed across plans
- All subscriber bands have the same eligibility for approved sending speed. Postly does not assign a slower daily rate to a lower subscriber band. Available capacity is shared across active senders and remains subject to sender health and provider approval.
- Current verified provider ceiling
- At the 28 October 2026 inspection, the existing sending service had AWS approval for 63,400 recipients per rolling 24 hours and 14 recipients/second. These are shared service ceilings, not a reservation for each customer. A requested increase is not approved capacity. Check Email → Overview → Sending details for the current verified limits and remaining capacity before a time-sensitive campaign.
- Product email protection
- Customer marketing and essential login and service emails are being separated. While they share a provider account, marketing reserves capacity for essential mail. Full approved marketing capacity becomes available only after the separate marketing account is ready and verified.
- Processing speed
- Governed by approved sender capacity, provider quotas, worker capacity, and safety checks. No universal emails-per-second benchmark is currently published.
- Accepted
- The sending provider accepted the recipient request. It does not prove final delivery. Accepted recipients count toward a legacy send-based allowance; subscriber-based plans include unlimited sends.
- Delivered
- The receiving server accepted the email according to provider feedback. It does not prove inbox placement.
- Delivery rate
- Unique delivered recipients divided by accepted recipient sends for the same campaign.
- Bounce rate
- Unique recipients with a bounce event divided by accepted recipient sends. Permanent bounces are suppressed.
- Complaint rate
- Unique recipients with a reported spam complaint divided by accepted recipient sends. Provider feedback coverage can vary.
- Open and click rates
- Unique recipients with a tracked open or click divided by confirmed deliveries. A missing delivery denominator is unavailable. Opens can be inflated by privacy tools or hidden by blocked tracking; automated scanners can affect clicks.
- Queue and report freshness
- Queue waiting time is separate from provider delivery time. Feedback is processed asynchronously; status is current only to its displayed update time.
Protection before speed
Managed sending requires verified sender setup, permission to contact subscribers, working feedback processing, and available allowance. New or unhealthy senders may be limited or paused. Unsubscribe, bounce, and complaint exclusions are checked again before dispatch. An ambiguous provider response stops automatic retries to reduce duplicate delivery risk.
Connected providers
BYOK customers use their provider’s sending capacity, audience rules, and available reporting. Unsupported data is unavailable, not zero. Review the connected provider’s limits before planning a time-sensitive campaign.