Category: Email Deliverability

Practical guides to domain authentication, sender reputation, routing, and reliable email delivery.

Owner Approval Workflow: Save the Right Credentials

Use the Sendmux owner approval workflow with durable read credentials, explicit Sending approval and safe retries. Keep token roles and invitation state separate.

Sendmux Team15 days ago9m

Owner review and consent precede granting an agent sending access.

Multi-Tenant Email: Suppression and Isolation Checks

Build multi-tenant email around correct tenant attribution, scoped access and suppression. Check domain, provider and reputation boundaries before scaling.

Sendmux Team16 days ago15m

Multi-tenant email separates tenant identity and data from sending policy and limits.

SMTP vs Email API: Five Checks Before You Migrate

Compare SMTP vs email API through five developer checks: compatibility, connection behaviour, credentials, delivery feedback and migration recovery.

Sendmux Team17 days ago11m

SMTP and email API submission paths, with the reminder that acceptance is not delivery.

Email Retry Strategy: Five Steps to Safer Sends

Build an email retry strategy around failure classification, stable send identities, provider pacing and message expiry. Test uncertain acceptance before increasing attempts.

Sendmux Team18 days ago13m

Email outcome classification branches to wait and retry for temporary failures or stop and review for other outcomes.

AI Agent Deliverability: Sending Controls That Matter

Build AI agent email around verified identity, recipient permission, provider limits and a tested pause path. Separate documented requirements from cold-outreach conventions.

Sendmux Team19 days ago13m

AI agent email passes through identity, permission and limit checks before sending

Cross-Mailbox Search: RFC, CLI and API Guide

Compare RFC 7377, Zimbra, Microsoft Purview, and mailbox API patterns for safe, auditable searches across authorised inboxes.

Sendmux Team20 days ago6m

Three bounded mailboxes feeding a verified cross-mailbox search result through controlled fan-out

Mailbox API: A Developer's Guide to Agent-Scale Email

Build a reliable mailbox integration with scoped access, efficient retrieval, state-token sync, signed events, and retry-safe writes.

Sendmux Team21 days ago9m

A mailbox API loop connecting scoped access, efficient retrieval, state tokens, and live events

Clean Email HTML: 7 Steps to Avoid Gmail Clipping

Separate byte reduction, HTML sanitisation, email-client rendering, and inbound thread cleanup with a seven-step developer workflow.

Sendmux Team21 days ago9m

Email HTML passing through byte, safety, rendering, and content checks

Email Delivery Logs: Query Patterns for Developers

Trace one message, read status and provider context, then widen the query only when the evidence points to a larger issue.

Sendmux Team23 days ago8m

A message ID narrowing into delivery status, provider, and attempt details

Gmail OAuth Sending: Fix 5 Errors That Stop Delivery

Fix Gmail OAuth sending failures by separating consent, token, scope, payload, and quota errors across the Gmail API and SMTP XOAUTH2.

Sendmux Team24 days ago11m