MailCull blog: field notes on email deliverability and list quality
2026
5 of 14
Email List Decay: How Fast Your List Rots and What to Do About It
Roughly 2% a month, but the range is wide and the drivers are predictable.
Bulk Sender Requirements in 2026: What Gmail, Yahoo and Microsoft Now Enforce
The 0.3% spam ceiling is the rule everyone quotes. The list-hygiene requirement is the one that catches people.
The Real Cost of a Dirty Email List (With the Actual Math)
Four costs, three of them invisible. Here is the arithmetic.
How to Reduce Your Email Bounce Rate: The Complete 2026 Guide
Bounce rate is a single number with five different causes underneath. Here's how to find yours and fix the right one.
How Often Should You Clean Your Email List? (Cadence by Sender Type)
Quarterly for most. Monthly for daily senders. Every campaign for cold outreach. Why the math works out that way.
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