Audience
AI agent builders that need an email API for AI agents
About Sendmux
Sendmux gives AI agents their own inbox and a controlled way to send email. Each agent can receive messages, read threads, handle attachments, send replies, and react to new mail through signed webhooks or Server-Sent Events.
Teams can send through Gmail OAuth, Outlook OAuth, SMTP providers, or managed Amazon SES. Sendmux can spread sending across providers with weighted routing, sender-domain routing, health checks, failover, and quotas by second, minute, hour, or day.
Developers get Mailbox, Sending, and Management APIs, OpenAPI docs, SDKs, the sendmux CLI, MCP tools, and Sendmux Skills. The platform also covers tenant isolation, mailbox-scoped API keys, custom domains, logs, metrics, and usage-based pricing with no per-seat or per-mailbox fees.
Other Popular Alternatives & Related Software
SMTP.com
Reliable SMTP relay and email delivery services. Powerful email delivery services that enable you to send and track high volume emails effortlessly. Integrate and start sending in minutes. All your transactional, email relay and email delivery needs under one roof. Whether you need a low-latency email delivery provider for your transactional emails, scalable infrastructure for high-volume sends or reliable backend solution for your marketing campaigns, SMTP is built to deliver. Reputation Defender is SMTP’s proprietary technology that uses big data to proactively monitor your email list health and safeguard your domain and IP reputation among ISPs by suppressing bad emails in your sends from hard and soft bounces. This ensures your delivery rates and inbox placement incrementally gets better over time.
Learn more
SendGrid
Email is the backbone of your customer engagement. The Twilio SendGrid Email API is the email service trusted by developers and marketers for time-savings, scalability, and delivery expertise. Our flexible Email API and proprietary Mail Transfer Agent (MTA), intuitive console, powerful features, and email experts make it easy to ensure all your email gets delivered in seconds and without interruption. Monitor engagement data and optimize deliverability with our Deliverability Insights dashboard.
Whether you’re sending 100 emails or 100 billion, SendGrid is built to scale. Integrate with our RESTful APIs and SMTP in minutes, with sample code libraries available in 7 languages, interactive docs, templates, and more.
Learn more
EmailLabs
EmailLabs is part of the Vercom S.A Group, which implements technology solutions in the CPaaS model. We are a cloud SMTP server infrastructure: Cloud SMTP & Email API.
With years of experience in sending to the most informed senders, we can make a measurable contribution to building email reputation and improving deliverability. We take care of standardization and security of both marketing, transactional and system messages of our customers.
Thanks to the in-depth knowledge of our experts, we are able to prepare the infrastructure to ensure appropriate throughput and increase the sending speed for any market and any mailbox provider.
Plug EmailLabs into your transactional sends - start sending in less than 5 minutes.
Learn more
Maildoso
Maildoso provides outbound mailboxes built for cold email, combining SMTP and Google Workspace infrastructure, fast setup, strong deliverability, and automated technical configuration. It helps teams diversify their sending strategy with reputable mailboxes built specifically for cold outreach, so campaigns are not dependent on one sender type, domain, or provider. Users can register domains directly in the dashboard or connect their own, enter mailbox names, and have SPF, DKIM, and DMARC auto-configured so mailboxes are ready to export and use with outreach platforms in minutes. Maildoso supports SMTP mailboxes, Google Workspace mailboxes, and combined setups, giving teams flexibility based on their sending strategy and target audience. It connects with popular sequencers and outreach tools such as Instantly, Smartlead, Saleshandy, and others, making it easier to move newly created mailboxes into active campaigns.
Learn more
Pricing
Starting Price:
$0.15 per 1000 emails
Free Version:
Free Version available.
Integrations
Company Information
Sendmux
Founded: 2026
Australia
sendmux.ai
Videos and Screen Captures
Unified Inbox
Other Useful Business Software
$300 Free Credits for Your Google Cloud Projects
Launch your next project with $300 in free Google Cloud credits—no strings attached. Test, build, and deploy without risk. Use your credits across the entire Google Cloud platform to find what works best for your needs. After your credits are used, continue with always-free tier services. Only pay when you're ready to scale. Sign up in minutes and start exploring.
Product Details
Platforms Supported
Cloud
Training
Documentation
Live Online
In Person
Videos
Support
24/7 Live Support
Online
