Should I always skip the greeting?

On cold first touches, yes. The character budget is too tight to spend on a greeting. On warm follow-ups or replies to existing threads, the greeting is fine because the preview unit is no longer the decision point.

Does the first line still matter if my subject is very strong?

Yes. A strong subject paired with a weak first line still under-performs a strong subject paired with a strong first line by 5 to 10 points. The two are read together. The subject sets the expectation, the first line confirms or breaks it.

How do I A/B test the first line without confounding the subject?

Hold the subject constant and vary the first line across two cohorts of 100 or more. Read the open rate after 48 hours. The clean split lets you isolate the first line's contribution.

Does the preview text setting matter for cold email?

Most B2B cold email tools do not support custom preview text the way marketing automation tools do. The first line is the preview text in cold email. Optimize what shows in the preview, do not waste it on a greeting.

First Line vs Subject Line: Which Matters More for Opens

The subject line earns the eye. The first line earns the click. Both load together in the inbox preview unit.

Why Both Matter

Most B2B inbox apps render subject + first line as a single preview block, read in roughly one second.

Preview Pane Mechanics

Gmail mobile shows ~30-45 chars of subject and ~50-60 of first line. Outlook desktop shows ~80 of each.

Relative Weight Data

Subject carries 60-70 percent of the open decision. First line carries 30-40 percent. Senior buyers weigh the first line more.

How to Write Each

Subject: 1-5 words, sentence case, specific. First line: open with the reference, no greeting.

Common Mistakes

Templated greetings, decoupled subject and first line, over-optimizing subject in isolation.