Reference

Migration Guide

Migrating to PostMTA is straightforward. This guide covers SendGrid, Mailgun, Amazon SES, and Postmark.

Migration Overview

  1. Create your PostMTA account and add sending domains
  2. Verify DNS records (DKIM, SPF, DMARC)
  3. Migrate contact lists and suppression data
  4. Update your code to use the PostMTA API
  5. Run a parallel send test period
  6. Switch DNS and decommission the old provider

From SendGrid

SendGridPostMTA
POST /v3/mail/sendPOST /v1/messages/send
personalizations[].substitutionstemplate_data or to[].substitutions
IP Pools via UIip_pool field in send payload

Migrating Suppressions

curl -X POST https://api.postmta.com/v1/suppressions/upload -H "Authorization: Bearer pmta_live_xxxx" -F "file=@sendgrid_suppressions.csv" -F "reason=bounced"

From Mailgun

MailgunPostMTA
POST /v3/{domain}/messagesPOST /v1/messages/send
Route-based forwardingWebhook event system
Mailgun mailing listsCampaigns with list segmentation

From Amazon SES

Amazon SESPostMTA
SES SendEmail APIPostMTA /v1/messages/send
Configuration SetsIP Pools plus webhooks
No built-in templatesNative template engine
No webhook deliveryFull event webhooks

Parallel Send Testing

Before fully switching, run both providers in parallel to verify deliverability parity.

Migration Support

Enterprise customers receive complimentary migration support. Contact sales to get started.