Postmark vs. Transmit:
The "Dedicated IP" Gatekeeper
Postmark is beloved for a reason. But their strict approval policy creates a dangerous ceiling for growing SaaS platforms.
Postmark acts as a gatekeeper, requiring manual approval and >300k emails/month sending volume before letting you buy a Dedicated IP. Transmit + AWS SES gives you this capability on Day 1.
- Postmark forces you onto a Shared IP unless you have massive volume (300k+).
- In Fintech/Healthtech, sharing an IP with other startups is a compliance risk.
- Transmit allows you to use AWS SES Dedicated IPs ($24.95/mo) immediately, with no approval gates.
- You get the same deliverability, but you own the asset.
01. The Gatekeeper Problem
Postmark's greatest strength is their deliverability. They achieve this by aggressively filtering who they let on their platform.
This is great for them. It is terrible for you if you are a legitimate business that just hasn't reached "Scale" yet.
Error: Volume Requirement Not Met
"Your account must consistently send 300,000 emails per month to qualify for a dedicated IP. Please continue using our (shared) transactional pool."
The "Use It or Lose It" Trap
Seasonal Senders Beware
Postmark documents state that if your volume drops below 20k/week for 4 weeks, your IP may require "Re-Warming". If you built a reputation for Black Friday, you might lose it by Christmas.
Mandatory Managed Warmup
You cannot control your warmup schedule. Postmark enforces their own throttles. If you need to migrate 5M users today, you can't. You are capped.
Warning: Warmup Throttle Active
"Only 5,000 emails were sent via Dedicated IP. 45,000 were routed to Shared Pool due to daily warmup limit."
The Transmit Workaround:
You don't need "permission" to buy a Dedicated IP on AWS. You just run one command (or click one button in Transmit).
Total time: 2 seconds. No support ticket required.
The "Noisy Neighbor" Risk in Fintech & Healthtech
If you are sending HIPAA-compliant notifications or Banking Alerts, you cannot afford to be on a Shared IP.
Even the best managed pool (like Postmark's) has "Neighbors." If a Crypto app on your node gets flagged by Spamhaus, your MFA codes might land in spam for 4 hours while they mitigate.
- Postmark Shared IP
You trust their vetting process. You share a reputation with 10,000 other customers.
- Transmit (AWS Dedicated IP)
You own the IP ($24.95/mo). You are the only tenant. Zero noisy neighbor risk.
03. Stop Renting. Start Owning.
Tenant (Postmark)
- Manual Approval Gate
- Forced "Re-Warming"
- Use-it-or-lose-it Policy
Owner (Transmit)
- Day 1 Access
- You Control the Slope
- Permanent Asset Ownership
Mastering Your IP Reputation
Owning an IP is step one. Warming it up without landing in spam is step two. Learn how Transmit automates the infrastructure for you.