ai-ro.dev — Email Deliverability & Infrastructure

Mail that reaches the inbox because the decision is right.

About

I work with email infrastructure for a living. I do not sell software. I do not run a SaaS. I am a consultant and engineer who designs, builds, and maintains high-volume email systems for companies that need them to work.

New engagements typically arrive through referral — from prior clients, partner MSPs, and ESP account teams who have seen the work firsthand. There is no marketing funnel behind this practice.

Services

Service	Description
Infrastructure Design	Design and deploy SMTP relays, PowerMTA clusters, Mailwizz instances, containerized senders on Kubernetes, self-hosted Linux VPS environments.
Authentication & DNS	End-to-end DNS for sending: SPF, DKIM, DMARC, BIMI, MTA-STS, TLS-RPT. Ongoing monitoring across Cloudflare, Route 53, or self-hosted BIND.
IP & Domain Warmup	Structured warmup protocols for new IPs and domains. Reputation recovery for damaged infrastructure.
Deliverability Audits	Inbox placement audits, blacklist removal, engagement analysis, list hygiene protocols.
DevSecOps for Email	Hardened build and deploy pipelines for sending stacks. Secret management, egress firewalls, image signing, and policy gates before anything touches production IPs.
Enterprise Consulting	AMS setup, team training, SOP documentation, ongoing retainer support.

Technologies

Click any item for a short note.

PowerMTA
Commercial high-throughput MTA used for outbound relay clusters at ISP scale.
Postfix
Open-source MTA. Preferred for self-hosted transactional and relay setups.
Exim
MTA still common in cPanel and legacy hosting environments.
Haraka
Node-based SMTP server used for programmable inbound and outbound pipelines.
Mailwizz
Self-hosted EMA for managing lists, campaigns, and delivery servers.
AWS SES
Amazon's SMTP/API sending service. Cheap, scalable, requires reputation work.
ESPs
Mailgun, SendGrid, Postmark, SparkPost, Mailjet/Brevo, UniSender, Instantly, and other commercial relays. Used for outbound streams, transactional mail, dedicated IPs, subuser isolation, event webhooks, and multi-region sending.
DNS
SPF, DKIM, DMARC, BIMI, MTA-STS, TLS-RPT records. Authored and monitored across Cloudflare, Route 53, and self-hosted BIND.
rspamd
Inbound filtering and scoring engine. Used for feedback loops and abuse handling.
OpenDKIM
DKIM signing daemon for Postfix and Exim deployments.
Kubernetes
Container orchestration for MTA fleets and supporting services. Helm charts, HPA, per-IP pod affinity.
Docker
Containerization of MTAs, signers, feedback processors, and warmup agents.
Terraform
Infrastructure-as-code for sending IPs, DNS zones, VPCs, and firewall rules.
Ansible
Configuration management for bare-metal and VPS MTA nodes.
nftables / iptables
Host-level firewalling. Egress control on port 25, rate limiting, connection shaping.
WAF
Web application firewall in front of tracking, unsubscribe, and API endpoints. Cloudflare and AWS WAF.
DevSecOps
CI/CD with secret scanning, SBOMs, signed images, and policy-as-code gating deploys to production senders.
HashiCorp Vault
Secret storage for DKIM private keys, API tokens, and MTA credentials.
Prometheus + Grafana
Queue depth, deferral rate, bounce class, and reputation dashboards.
Loki / ELK
Centralized MTA log aggregation for forensics and deliverability triage.
eBPF
Low-overhead tracing of SMTP sessions and TLS handshakes on busy relays.

Selected Work

E-Commerce Platform — 10M subscribers

Migrated from shared ESP to self-hosted PowerMTA cluster on Kubernetes.

Reduced spam placement from 12% to under 2%.

Infrastructure cost reduced 40%.

SaaS Company — Transactional email

Rebuilt DNS from scratch and shipped a DMARC reject policy behind CI checks.

Improved inbox rate from 78% to 97%.

Brand impersonation attempts dropped to zero.

B2B Agency — Cold outreach system

Built dedicated IP warmup from cold start with egress-firewalled sender pods.

Established positive sender reputation in 45 days.

Sustained 85%+ inbox rate on B2B domains.

Writing

Cold Email Deliverability: Building B2B Outreach Infrastructure
Dedicated IPs, egress firewalls, DNS authentication, and reputation warmup.
B2B Outreach Domain Strategy
Sending domain and subdomain architecture that isolates outreach reputation.
Choosing an ESP for B2B Outreach
Practical notes on Mailgun, SendGrid, Postmark, SparkPost, SES, Mailjet/Brevo.

Contact

Email: hello@ai-ro.dev
Response time: usually within 24 hours.

I take on a small number of projects at a time. Send a short note about what you are sending, what is going wrong, and what the stack looks like today. If it is a fit, we will talk.