How to write a campaign that gets read

We often confuse "nice email" with "effective email." A polished template with ten images is useless if it ends up unopened, or closed at the second line. Reading an email happens in three moments: the subject decides the open, the first lines decide the read, the call to action decides the click. Each is worked on separately.

The subject line: the only text everyone sees

Your subject is read by 100% of recipients — the content, by a fraction. So that's where most of it is decided.

• Short. Many clients cut off past 40 characters on mobile, where most email is read.
• Concrete over clever. "Your July invoice" beats "A surprise awaits you." Artificial curiosity wears out fast and erodes trust.
• No spam trigger words. "Free!!!", "urgent", all-caps and bursts of exclamation marks weigh on your deliverability as much as on your credibility.

The preheader: your second subject line

The line of text shown after the subject in most clients is often wasted on "View this email in your browser." It's a second chance to convince — use it to extend the subject, not for plumbing.

Structure: one idea, one action

A marketing email is not a catch-all newsletter. The rule that works:

1. A hook that picks up the subject's promise, without betraying it.
2. A short body developing a single message.
3. One call to action, visible without scrolling.

Several buttons pointing to several places dilute the decision. A reader offered three choices often makes zero.

The call to action: a verb, a clear expectation

"Click here" says nothing. "Book my seat," "Read the study," "Download the guide" say exactly what will happen. People click when they know where they're going.

Unsubscribe: an obligation, not an admission of failure

A clear unsubscribe link is required by law and by mailbox providers. Hiding it holds no one back: it simply pushes annoyed readers to hit "spam" instead — which durably damages your sender reputation. A clean unsubscribe beats a complaint.

Test before sending

Send the campaign to yourself. Read it on mobile. Check that links work, that variables — first name, company — fill in, and that the email stays readable without loading images: many clients block them by default. With AgentMail, a campaign starts from a template then becomes a copy you edit freely. You begin from a clean base and adjust the message without starting over on every send.