Subject lines
Drawn from what you already wrote.

Write the message, open the sparkle beside the subject and pick Write a subject from the body. The proposed line fills the row, and the same menu rewrites one you already have.

In short

What is an AI subject line generator?

The subject is the line a reader sees before opening anything. A generator reads the finished message and condenses its point into that line.

100characters

The limit a subject written from the body is asked to stay under

5

Ready-made rewrites, plus one you describe

3 or 5

Options per rewrite, each showing its length

How it works

It reads the body you wrote

The menu's first item reads what you typed and your writing profile, never the recipients or the attachments. With nothing typed, it asks for the message first.

Rewrite the one you have

Ask for it shorter, longer, rephrased, more formal or more casual, or say what should change. Choose three options or five, and Use this puts one in the row.

A draft fills a blank subject

Ask the body's sparkle to write the message while the subject is empty, and the subject is written first, from your note. The draft follows.

What you get

In the product today

Beside the subject

One sparkle at the end of the subject row holds every option.

Writing profile

The writing profile built from sent mail shapes the subject, as it shapes drafts.

Straight into the row

A line written from the body lands in the row, ready to edit.

New mail and forwards

Both carry the sparkle. A reply keeps its original subject.

Good practice

Getting the most out of it

  1. 01

    Finish the body first

    The line comes from the body, so ask once the point of the message is on the page.

  2. 02

    Rewrite, do not replace

    Writing from the body overwrites the row, so use Shorter or Rephrase to build on a subject you started.

  3. 03

    Watch the count

    Each option shows its length, and phones cut long subjects short.

Questions

Asked often

Keep going

Works well with

Draft from a note

Give it the gist and get the whole body back, in the first person as you.

Your writing style

Drafts are shaped by how you actually write.

Writing tools

Formatting, inline completion and emoji shortcodes in the composer.

Start

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Email infrastructure for businesses, AI, agents and personal email. Built for scale, privacy and control. Everything email should have had from day one.

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