How to fix low open rates for cold email

Low open rates usually mean the inbox never trusted the message, or the subject failed the two-second relevance test. Fix the infrastructure and the words in that order.

Check deliverability before rewriting copy

Confirm authentication (SPF, DKIM, DMARC), domain age and reputation, list quality, and sending volume. A clever subject cannot rescue mail that never reaches the primary inbox. Remove obvious invalid addresses and pause if bounce rates climb.

Improve the subject and preview text together

Readers see both. Make them consistent, specific, and short. Test whether your “From” name looks like a person the account would recognize. Avoid misleading Re: prefixes.

Reduce spray-and-pray patterns

Narrow the audience so each subject can mention something real. Smaller, better-targeted batches often lift opens more than another synonym for “quick question.”

Separate open rate from reply rate

Opens are imperfect, especially with privacy protections. Use them as a directional signal, then optimize for replies and meetings. If opens are fine but replies are not, the problem is the body and the ask—not the subject alone.

What to do next

Run one focused audit this week: authentication, bounce rate, and ten subject lines rewritten for a single segment. Measure the next send before changing five things at once.