What is a Subject Line? – help.customers.ac

The subject line tells the recipient what your email is about. It should be short enough to scan and consistent with the content.

Useful guidelines

Use plain, relevant language.

Make the topic clear without exaggerated promises.

Keep personalization accurate and natural.

Test alternatives with similar audiences.

Do not use fake "Re:" prefixes, imply a meeting that never happened, or invent urgency. Looking like an internal message is not a reason to mislead the recipient.

Illustrative examples

"Question about your onboarding"

"An idea for [company]"

"Customer support workflow"

Choose an example only when it accurately describes your email. Judge results through useful replies and conversations; tracking pixels can make open-rate comparisons misleading.