1. Unmetered incoming email

THRD does not enforce a monthly billing quota on accepted incoming messages. The incoming counter is observational and never becomes a monthly billing denial. No monthly incoming-message quota applies.

2. What unlimited does not mean

THRD is an email runtime, not an unlimited-storage or archival service. Unlimited incoming email does not include unlimited message size, attachments, AI analysis, compute, processing, retention or outbound delivery.

3. Baseline Free limits

Incoming message size: 5 MB including MIME encoding.
Raw MIME and attachments: retained for 72 hours.
Sanitized text and HTML: retained for 7 days.
Message metadata: retained for 30 days.
Safe replies: 25 recipient units per UTC month and at most 5 per UTC day.

4. Service-protection controls

THRD may bound connection counts, concurrent message transfers, in-flight bytes, MIME depth, part count, header bytes, decoded attachment bytes and processing time. Traffic may be throttled, temporarily rejected, quarantined or paused when it exhibits spam, malware, denial-of-service, recipient enumeration, malformed MIME, duplicate storms, automated loops, account farming or resource exhaustion.

5. Outbound safety

Free is reply-only and cannot be used for campaigns, new recipients, CC, BCC or customer SMTP relay. Every plan enforces suppressions, recipient authority and policy. Paid outbound capacity does not grant permission to contact a recipient.

6. Changes and contact

THRD may adjust technical limits to protect reliability and abuse resistance. Material customer-facing changes will be documented when circumstances permit. Questions may be sent to [email protected].