Retarus Transactional Email: Fast, Reliable, and Secure

We offer guaranteed throughput rates, first-class inbox placement, and increased customer engagement through our reliable transactional email delivery.

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Reta cares about email delivery!

98% + delivery rates and unlimited capacity! Scale your business and reduce latency. No more waiting for emails!

High Performance

Send high volumes of emails via API from your business applications with contractually guaranteed throughput rates without straining your own infrastructure.

Improve Your Reputation

Retarus is a leader in reputation management and CSA (Certified Senders Alliance) certified. We protect your domain, IP reputation and sender score.

Get The Most Out Of Your Email

Our comprehensive APIs simplifies your email workflows. Outsource resource-heavy capabilities like Templating, Sanitization, Optimizations, Rendering and more.

Expansive Compliance and Certifications

Adhere to local data protection regulations and 100% GDPR-compliance. We process data in self-operated data centers in Germany, Switzerland, US, or Asia.

Retarus Transactional Email Data Flow

  • SMTP Basic authentication
  • SMTP Source IP authentication
  • REST Basic authentication

  • DMARC
  • DKIM
  • SPF
  • Unsubscribe list
  • Suppression list
  • Bounce management
  • CSA Certified IPs

  • Template rendering
  • Address rewriting
  • Trace and Recover
  • Campaign support

  • Anti virus multiscan
  • Message signing
  • Secure document handling
  • 3rd party archiving

  • Spam Score Check Report
  • Feedback Loop Reporting
  • Open-/Link Tracking
  • Bounce Reporting / Response Manager
  • Trace and Recover

  • SMTP Basic authentication
  • SMTP Source IP authentication
  • REST Basic authentication

  • DMARC
  • DKIM
  • SPF
  • Unsubscribe list
  • Suppression list
  • Bounce management
  • CSA Certified IPs

  • Template rendering
  • Address rewriting
  • Trace and Recover
  • Campaign support

  • Anti virus multiscan
  • Message signing
  • Secure document handling
  • 3rd party archiving

  • Spam Score Check Report
  • Feedback Loop Reporting
  • Open-/Link Tracking
  • Bounce Reporting / Response Manager
  • Trace and Recover

Who is Retarus Transactional Email for?

One size does not fit all. Our clients rely on Retarus for highly capable, high-volume emailing to their end customers. Whether for critical communication, increasing customer engagement, application integration, or specialized requirements.

Software Vendors, Platform Businesses

Our ideal customers are fast-growing who rely on B2C emails for confirmations, invoices, and marketing, and need flexible, dependable solutions for time-sensitive, process-driven communications. Their workflows often trigger multiple messages per customer action, making them perfect candidates for scalable, reliable email solutions.

Large Enterprises

Large Enterprises

Diverse recipients and communication preferences, complex business workflows, and high-volume demand can quickly strain email infrastructure. Enterprises need an intuitive solution, especially when their Email Infrastructure is complex with on prem, cloud, legacy, or 3rd party applications, devices, subsidiaries.

Large Enterprise

Highly Regulated Industries

Sending or receiving critical information such as invoices, order confirmations, or time-sensitive notifications cannot afford any delays or land in spam. Strict compliance regulations in sectors such as healthcare, manufacturing, retail, finance, and legal force businesses to find a reliable, secure email solution.

Customer Ratings and Reviews

“With Retarus WebExpress our marketing department is able to take action much faster than before. Fax campaigns can now even be sent at short notice without difficulty.”

Read customer story Karl-Heinz Aupperle, Marketing Head, winkler Group

“Swift and simple filtering and prioritization of information are the basis of any effective communication process.”

Read customer story Peter Zündorf, Head of IT systems, Deutscher Sparkassen- und Giroverband (DSGV)

“The efficient, neat implementation did not only win us over, but also our business partners. One big automobile manufacturer expressly pointed out the quick reaction times and general expertise of the Retarus team.”

Read customer story Alexander Grothe, eCommerce Team Leader, Optibelt GmbH

“We send more than a million faxes every year, so we were looking for a service provider who could reliably handle our high fax volumes, even at peak times such as the run-up to Mother’s Day. Retarus met every single one of these requirements.”

Read customer story Marc Ober, IT Director, Interflora France

“We will eliminate all of Austrian Post’s remaining fax servers step by step replacing them with the appropriate Retarus services.”

Read customer story Reinhard Knie, Head of Solution Management CEE , Atos

Why Choose Retarus Transactional Email?

Highest Throughput Rates

Delivery rate of 98%+ far above market average, guaranteed throughput of 10+ million emails per hour. All contractually agreed.

Advanced Reputation Management and Beyond

  • Unparalleled inbox placement (average sender score = 99, industry average is 85). Dynamic IP routing according to sender domain, CSA certification, bounce management. SPF, DKIM and DMARC implementation to maintain a high inbox placement.
  • Convey trust, confirm email authenticity, and increase email acceptance with Messaging Signing.

Auditable Data Centers

  • Data centers in the United States, in Europe and in the APAC region
  • Retarus’ data centers are self-operated, self-sufficient, and redundant
  • No hyperscalers, local data processing available
  • Multi-client capability thanks to multi-domain configuration. Failover and load balancing options available
  • All data centers are operated according to the latest standards and fulfill strict requirements: EU GDPR, HIPAA, Sarbanes-Oxley, or PCI DSS, CAN-SPAM, TISAX

Fast Implementation

  • Our experienced team handles every detail of onboarding and go-live.
  • Devoted service management makes sure you get the most out of your email.

Real People, Real Support

  • No call center nor chatbots
  • You get experts who know what they are doing
  • We become part of your team from scope, migration, production and Go-live

Transactional Email Tailored to You

Retarus Transactional Email

Native APIs & Gateways

Easily integrate Retarus Transactional Email into existing workflows via APIs including REST and SMTP to reduce complexity and bolster your landscape.

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Transactional Email for Business Applications

Retarus Transactional Email integrates directly via business applications including SAP, Microsoft, Salesforce, or ServiceNow.

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Frequently Asked Questions

Is there documentation available about compatibility and feature details?

Yes. Retarus Transactional Email supports numerous types of business applications and has a rich feature set. Detailed feature overviews and documentation can be found here.

Is the implementation of transactional email difficult?

Not with Retarus. Enterprises often have complicated requirements or critical processes that cannot be interrupted, but we have experience from thousands of successful migrations and onboardings with many of the world’s leading companies.

Where can I find out more?

Read our case studies and analyst reports. Check out our corporate blog and upcoming webinars, and feel free to book a demo. We’re always happy to help.