Sendmux is email inbox API for AI agents - multi-provider SMTP routing, dedicated agent mailboxes, and token-saving structured parsing in one API. The Sendmux blog covers AI agents, email deliverability, and the infrastructure powering agentic communication.
Google Workspace can create users through an API. SendGrid can receive email. Both facts are true. Neither one settles the infrastructure decision for an agent fleet. Email for AI agents becomes an infrastructure problem when email is part of a long-running software workflow. The useful question is
Choose between SMTP ports 587 and 2525, match the correct TLS mode, and diagnose blocked connections without weakening authentication or certificate checks.
Queue email before sending, enforce the right counters, and handle HTTP or SMTP pressure without delaying urgent messages or creating duplicates.
Map every SaaS sending identity, process DMARC aggregate reports, and move from monitoring to enforcement without breaking critical email.
Build a bounce handling pipeline that classifies DSNs, avoids duplicate retries, enforces recipient suppression, and processes signed email events.
Learn how to batch cold email with consent, authentication, quota-aware queues, retry controls, suppression, and measurable stop signals.
An AI agent can send an email with one API call. The engineering starts when someone replies. An email inbox for AI agents is a mailbox that has an address, can store messages, can deliver events, and can receive and send messages in a controlled way. It is programmatically accessible and
Learn how DMARC alignment connects the visible From domain to SPF or DKIM, when relaxed and strict modes pass, and how to diagnose failures.
Learn how Message-ID, In-Reply-To, References, provider thread IDs, and raw-header checks keep email replies in the right conversation.
Choose an email attachments API pattern for base64, binary uploads, reference IDs, inbound downloads, agent workflows, security, and provider limits.
