Email · October 2026

Customer.io vs Mailgun: which do AI models pick?

Customer.io and Mailgun are about even on being recommended first (0% vs 0%). Customer.io and Mailgun are about even on being installed in AI-built apps (0% vs 0%).

Customer.ioMailgun
Recommended first
0%
0%
Mentioned
13%
68%
In AI-built apps
0%
0%
Customer.ioMailgun
Rank among email tools recommended firstnot rankednot ranked
Rank in AI-built appsnot rankednot ranked
More detailCustomer.io pageMailgun page

Based on 180 recommendation answers and 120 AI-built apps. Differences under about 7 points are within noise.

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Customer.io breakdown Mailgun breakdown

Measured 2026-10-01 with claude-sonnet-5.5, gpt-6.1-sol, gemini-3.8-flash, grok-4.7, deepseek-v4.1-flash, qwen3.8-max-prime, 5 runs per recommendation prompt and 5 per build prompt, via public APIs with no system prompt. Methodology. DefaultRank is independent and not affiliated with any tool vendor or model provider.