An email content checker found no subject line. A missing or placeholder subject makes the email hard to understand in the inbox. Write the main reason to open the email in one short sentence. Avoid vague labels such as `Update` unless the preview text explains why the email is useful. Make sure the subject matches the email body. Send a test email and check that the full subject is clear on mobile.

An email content checker found a subject that may be clipped in mobile inboxes or may hide the main point. Move secondary information into the preview text. Put the most important words near the beginning of the subject. Remove filler words and repeated context. Send a mobile test and confirm that the main promise is visible in the inbox.

An email content checker found repeated punctuation or long all-caps text. These patterns can make a legitimate campaign look pushy. Rewrite the subject in normal sentence casing. Use one clear promise instead of urgent-sounding wording. Keep punctuation simple. Mention a deadline only when the deadline is real.

An email content checker found no preview text. Inboxes may show random body text, footer text, or unsubscribe text instead. Write one short preview line that supports the subject. Do not repeat the subject word for word. Use the preview to explain who should read the email, what changed, or why the message matters. Send a test email and check that the subject and preview text work well together.

Write the Subject and Preview Text

The subject gets attention. The preview text gives subscribers another reason to open the email.

4 min read

Overview

The subject line makes the first promise. The email body must keep that promise. If the subject promises one thing and the body says another, subscribers will trust future emails less.

Preview text is the short snippet that many inboxes show beside or below the subject. Use preview text to add context. Do not repeat the subject or leave default text pulled from the email body.

What to Check

Make the subject specific. Your March account summary is ready is clearer than Important update.
Avoid tricks that may increase opens but reduce trust, such as fake replies, false urgency, or misleading offers.
Use preview text to explain who should read the email, what changed, or why the message matters.
Check the subject and preview text on a phone. Long text may be cut off in mobile inboxes.
For recurring newsletters, keep the format consistent enough that subscribers recognize it.

Fix Common Issues

Missing Subject Line

An email content checker found no subject line. A missing or placeholder subject makes the email hard to understand in the inbox.

Write the main reason to open the email in one short sentence.
Avoid vague labels such as Update unless the preview text explains why the email is useful.
Make sure the subject matches the email body.
Send a test email and check that the full subject is clear on mobile.

Long Subject Line

An email content checker found a subject that may be clipped in mobile inboxes or may hide the main point.

Move secondary information into the preview text.
Put the most important words near the beginning of the subject.
Remove filler words and repeated context.
Send a mobile test and confirm that the main promise is visible in the inbox.

Overly Loud Subject

An email content checker found repeated punctuation or long all-caps text. These patterns can make a legitimate campaign look pushy.

Rewrite the subject in normal sentence casing.
Use one clear promise instead of urgent-sounding wording.
Keep punctuation simple.
Mention a deadline only when the deadline is real.

Missing Preview Text

An email content checker found no preview text. Inboxes may show random body text, footer text, or unsubscribe text instead.

Write one short preview line that supports the subject.
Do not repeat the subject word for word.
Use the preview to explain who should read the email, what changed, or why the message matters.
Send a test email and check that the subject and preview text work well together.

Use Segments and Exclusions

Write the Email Body