I was stuck at around 20% open rates for what felt like forever. Tried the whole song and dance - rewriting subject lines, fiddling with send times, even cleaning my list. Marginal improvements at best. Bloody frustrating.
The real unlock? Two things, and neither was copy tweaks.
First, deliverability infrastructure. Getting DMARC, DKIM, and SPF properly aligned plus moving to a dedicated IP with an actual warmup schedule (not just flipping a switch) gave me an instant 8-point bump before I changed a single word. Second, ruthless segmentation by recency and behaviour, not demographics. People who clicked anything in the last 90 days got one cadence, 90-180 days got a re-engagement flow, beyond that got suppressed until they opted back in.
Shrinking the active list feels terrifying, but your domain reputation will thank you. The open rates reflect a healthier audience, not a vanity metric. That's what finally broke me past 30%.