Best AuthSMTP Alternatives & Competitors in 2025

turboSMTP is a reliable, powerful, easy-to-use SMTP server that maximizes the deliverability of all...

Key turboSMTP features:

Ease of Use Reliability Customer Support Analytics and Reporting

SMTP provides scalable affordable email infrastructure for all your sending needs.

Key SMTP features:

Reliability Scalability Analytics Integration

Warmup Inbox is a tool that automates the process of warming up your email inboxes, raising your sender reputation and inbox health automatically.

Key Warmup Inbox features:

Automatically warms up domain to be ready for cold email Improve Email Deliverability Improve Domain Reputation Improve IP Reputation

Try for free paid Free Trial $12.0 / Monthly (Per inbox, per month.)

SMTP2GO is the scalable, reliable email deliverability solution. Worldwide servers, a robust API, and powerful reporting set us apart. Try our free plan!

Key SMTP2GO features:

Reliability Global Infrastructure Detailed Reporting Easy Integration

WP Mail SMTP is an online platform that facilitates users with multiple facilitation.

Key WP Mail SMTP features:

Improved Email Deliverability Easy Configuration Broad Integration Email Logs

EmailSuccess is an advanced MTA built to handle the most critical reliability, performance, security, and deliverability requirements.

Key EmailSuccess features:

Scalability Deliverability Advanced Analytics Integration Capabilities

Google's encompassing suite of cloud-based business apps.

Key Google Workspace features:

Integrations Collaboration Cloud Storage Security

Jira Service Management is an online development platform that facilitates users with multiple services.

Key Jira Service Management features:

Integration with Atlassian Suite Customizable Workflows Automation Capabilities Scalability

Learn why more developers choose SendGrid for their email deliverability service to send transactional emails triggered by web apps. Get started for free.

Key SendGrid features:

Scalability API Integration Deliverability Analytics

Postmark is the easiest and most reliable way to be sure your important transactional emails get to the inbox. Simply & reliably parse recieved email to JSON for your webapp.

Key Postmark features:

High Delivery Rates Fast Sending Speed User-Friendly Interface Detailed Analytics

Open Source

CritSend is a SMTP relay for developers.

Mandrill is a new way for apps to send transactional email. It runs on the delivery infrastructure that powers MailChimp.

Key Mandrill features:

Scalability Deliverability Integration Analytics

Email Validation & Email Verification reduces bounce rates up to 98%. Rapidly verifying email addresses has never been easier, just drag drop and deliver!

Key BriteVerify features:

Accuracy Speed Ease of Use API Integration

Marketing & transactional email delivery platform.

Key SocketLabs features:

Deliverability Scalability User-friendly Interface Analytics and Reporting