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APPLICATION SENDING

For applications that already send mail

SMTP Relay or REST API. Dedicated IPs from the entry plan, not as an upsell.
Included products
Common uses
  • · Drop-in replacement for SendGrid Pro or Mailgun
  • · Transactional email under 1M/mo with dedicated IPs
  • · ERP, billing systems, internal tools that already speak SMTP
  • · Webhook-driven workflows in product code
DEDICATED INFRASTRUCTURE

For sending shapes that need real iron

Bare-metal Xeon servers, managed PowerMTA stack, your choice of MTA. EU data centres.
Included products
Common uses
  • · Sustained sending past 100K/hour
  • · Multi-stream isolation for ESPs and SaaS platforms
  • · Bring-your-own MTA (Postfix, Exim, KumoMTA, your PowerMTA)
  • · EU data residency with port 25 open by default
OPERATOR SERVICES

For the parts software cannot do alone

Cold-email infrastructure post-Spamhaus 2025, plus deliverability work done by humans.
Included products
Common uses
  • · Cold-email programs respecting Spamhaus 2025 / RETVec
  • · Deliverability audit + remediation on any sending stack
  • · Continuous warming and cousin-domain isolation
  • · Authentication, BIMI rollout, monthly DMARC processing
Compare against:
vs SendGrid vs Mailgun vs Postmark vs Amazon SES
Free tools:
DMARC checkerSPF flattenerDKIM testerBlocklist lookup
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Featured outcome
Case study
Hamburg e-commerce, peak season recovery

Gmail placement collapsed from 96% to 38% one week before Black Friday. Recovered to 91% by Black Friday morning.

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Blog · 31 notes from the operator desk

Operator notes

Long-form pieces from the operator desk. Most are about deliverability shifts after Spamhaus 2025, RETVec, the 2024 DMARC enforcement, and the receiver-side changes that keep redrawing the landscape.

Operator note

When PowerMTA becomes the right move

Henrik Bjørnstad, Principal Engineer
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TLS for SMTP: upgrading transport encryption for outbound email

Tuuli Korhonen, Security Engineer
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SMTP relay migration planning for growing teams

Mikael Vainiomaa, CEO and Co-founder
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SMTP relay for operational alerts and system notifications

Elin Bergström, Senior SRE
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SMTP relay for billing systems and legacy applications

Saara Niemelä, Email Infrastructure Engineer
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SMTP fundamentals for application developers sending email from code

Maja Søndergaard, Developer Relations
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Server hardening basics for email workloads

Tuuli Korhonen, Security Engineer
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Sender reputation fundamentals: how inbox providers evaluate senders

Elin Bergström, Senior SRE
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Scaling outbound email beyond shared hosting: what changes technically

Ingrid Halvorsen, Platform Engineering Lead
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PowerMTA vs basic SMTP servers for high-volume sending

Saara Niemelä, Email Infrastructure Engineer
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PowerMTA routing, IP pools and stream design basics

Saara Niemelä, Email Infrastructure Engineer
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SMTP Relay vs Email API: which one fits your sending stack in 2026?

Elin Bergström, Senior SRE
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Planning IP reputation and deliverability for expanding sending programs

Ingrid Halvorsen, Platform Engineering Lead
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IPv6 email sending: practical considerations for high-volume senders

Henrik Bjørnstad, Principal Engineer
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How to choose between dedicated infrastructure and shared sending layers

Ingrid Halvorsen, Platform Engineering Lead
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Feedback loops and complaint handling for bulk senders

Ingrid Halvorsen, Platform Engineering Lead
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Email authentication for growing senders: SPF, DKIM and DMARC in practice

Mikael Vainiomaa, CEO and Co-founder
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Email API for SaaS products and event-driven workflows

Maja Søndergaard, Developer Relations
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Domain separation for cold email teams

Saara Niemelä, Email Infrastructure Engineer
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DMARC in practice: early lessons from the first wave of adopters

Annika Lindqvist, Senior Deliverability Engineer
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DKIM signing for transactional email: a practical setup guide

Annika Lindqvist, Senior Deliverability Engineer
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Designing transactional email workflows around application events

Maja Søndergaard, Developer Relations
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Designing an IP warmup schedule for new sending infrastructure

Saara Niemelä, Email Infrastructure Engineer
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Deliverability monitoring that catches problems before they scale

Annika Lindqvist, Senior Deliverability Engineer
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Cold email warmup expectations for serious outbound programs

Annika Lindqvist, Senior Deliverability Engineer
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Building reliable API-based email for account lifecycle messaging

Elin Bergström, Senior SRE
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Building a dedicated MTA stack: choosing between PowerMTA, Postfix and Exim

Saara Niemelä, Email Infrastructure Engineer
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Authentication alignment and policy review for multi-domain senders

Annika Lindqvist, Senior Deliverability Engineer
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Dedicated email servers: when isolation starts to matter

Ingrid Halvorsen, Platform Engineering Lead
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Transactional email infrastructure: when SMTP relay is enough and when it stops being enough

Mikael Vainiomaa, CEO and Co-founder
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Cold email infrastructure without avoidable deliverability mistakes

Annika Lindqvist, Senior Deliverability Engineer
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