MTA Capacity Planning Calculator

PowerMTA vs Postfix at Scale

• Postfix: Excellent for up to ~100k emails/hour with proper tuning. Free, widely supported.
• PowerMTA: Designed for high-volume production sending. Per-domain throttling, detailed logging, and bounce categorization built-in.
• Queue management: At high volume, queue depth grows faster than delivery can drain it. SSD storage is critical.

For volumes above 500k/day, PowerMTA's per-domain connection management and real-time reporting significantly reduce operational overhead compared to Postfix.

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