Migration Guide
The complete guide to migrating your email sending from Mailgun to dedicated IPs — with full IP warming support, zero downtime, and measurable inbox placement improvements.
Migrating from Mailgun / Sinch Mailgun to Dedicated Infrastructure
Mailgun / Sinch Mailgun is a developer-focused email delivery API service. It works well at lower volumes and for teams that want managed sending without infrastructure decisions. But senders who reach a certain scale — or who've experienced blacklisting, shared IP contamination, or deliverability plateaus — find that the lack of IP isolation and control becomes the bottleneck. This guide covers the complete migration process from Mailgun / Sinch Mailgun to dedicated email infrastructure.
Quick facts: Mailgun vs. dedicated infrastructure
| Feature | Mailgun | Cloud Server for Email |
|---|---|---|
| IP type | Shared with thousands | Dedicated — yours only |
| IP reputation control | None — shared pool | Full — isolated per client |
| Blacklist monitoring | Basic or none | 50+ lists, every 4 hours |
| Sending volume visibility | Aggregate only | Per-IP, per-pool detail |
| IP warming | Auto/shared | Guided, per-use-case |
| ISP postmaster access | Limited | Full Postmaster Tools access |
| PowerMTA / Acelle / MailWizz | Not available | Available |
| Custom PTR records | No | Yes — per IP |
Why senders leave Mailgun
The most common reasons senders at 500K–50M emails/month outgrow Mailgun:
- Shared IP pools on Mailgun Foundation/Scale plans expose you to other senders' behavior
- Mailgun's dedicated IPs require self-managed warm-up without structured guidance
- Recent pricing changes have significantly increased costs for high-volume senders
- Deliverability support is reactive rather than proactive
- Limited control over retry logic and MTA configuration
Key benefits after migration
Zero code changes
Our Mailgun-compatible endpoint means updating base URL and API key is the entire migration
Dedicated IP pools
Separate pools for transactional and marketing with independent reputation tracking
Detailed reporting
Per-IP delivery metrics, bounce analysis, and ISP-level breakdown
Predictable pricing
Flat monthly infrastructure cost vs. Mailgun's volume-based pricing
Migration process: 1–2 weeks
Export Mailgun suppressions
Use the Mailgun API to export bounces (GET /v3/{domain}/bounces), unsubscribes (/unsubscribes), and complaints (/complaints) for all your Mailgun domains.
Note your domains and routing configuration
Document all Mailgun domains, routes, and webhook configurations. You'll recreate these on the new platform.
Update base URL in your application
Replace api.mailgun.net with mailgun.cloudserverforemail.com. Your existing Mailgun SDK code will work without any other changes.
DNS update
Replace Mailgun's DKIM CNAME records with TXT records from your new portal. Update SPF to replace include:mailgun.org with include:spf.cloudserverforemail.com.
Import suppressions and run test sends
Import all suppression data. Test sends from each of your sending domains before starting the warm-up.
IP warming
Mailgun migrations benefit from established domain reputation. Your account manager will schedule an accelerated warm-up based on your volume history.
Ready to migrate from Mailgun?
Our team manages hundreds of migrations per year. We'll review your current setup, configure your dedicated infrastructure, and guide your IP warm-up. Most clients see measurable inbox placement improvements within 30 days.