The glance
A subject line gets a glance on a lock screen, not a reading. This tester scores yours against the rules our 4,000,000-send corpus taught us, and names exactly what to cut.
Questions
Three to five words, under about 45 characters. Phone lock screens and inbox lists truncate the rest, and the truncated half is where most people put the point. Short survives; clever gets cut mid-word.
A resolved merge field, such as the prospect's company, a competitor, or a number, outperforms cleverness. An unresolved one produces “Hi ,” which is unrecoverable. The rule: personalise from the lead file, verify the field fills, never personalise from memory.
It buys one open at the cost of everything after it. The reader knows there was no prior thread; filters recognise the pattern too. It is the single most trust-destroying character sequence in cold email.
Free
Paste it, and the rule-set from 4,000,000 sends scores it. The report lands in your inbox in minutes, and a full three-step sequence written for your ICP follows from Hugo a few hours later.