To dictate an email in Superhuman, Spark or Thunderbird on a Mac, open a new message, click into the body, start Apple's built-in Dictation with the Microphone key or your Dictation shortcut, and speak. None of the three documents a dictation feature in its Mac app. Superhuman's Write with Voice and Spark's Siri dictation are documented for phones, and Superhuman says Write with Voice "isn't traditional dictation" at all. The main risk on a Mac is a send shortcut pressed too early.
Publisher note: SuprFlow publishes this guide and is one of the products discussed. Competitor details come from each company's own pages, checked on 3 October 2026. Prices and features change; confirm before you buy.
What voice features do these email apps document?
| App | Voice feature | On a Mac? |
|---|---|---|
| Superhuman | Write with Voice: tap the voice icon above the keyboard, "say what you want to write", and Superhuman AI turns it into "a polished draft in your tone." It can fill in To and Subject. All plans have it (Write with AI) | Documented for the iOS and Android apps |
| Spark | With Siri on iOS 27 you can "Dictate a reply, a reply-all, or a forward in your own words" and Spark sends it from the right account (Spark on iOS 27) | Documented for iPhone and iPad |
| Thunderbird | None. Mozilla's Thunderbird help pages do not describe a built-in dictation feature as of 3 October 2026; see Thunderbird keyboard shortcuts | Not applicable |
Superhuman's own FAQ is clear about the difference: "Instead of transcribing your words exactly as spoken, Superhuman AI turns your thoughts into a polished draft." If you want your exact words, use dictation. If you want an AI draft from a spoken outline and you are on your phone, Write with Voice is built for that. Accepting the draft does not send it.
How do you dictate an email with Apple Dictation?
Apple's Dictation guide for macOS 27 says "you can speak to enter text anywhere you can type it."
- Turn on Dictation once in System Settings → Keyboard → Dictation. On older macOS versions the wording may differ.
- Start a new message: C in Superhuman, Command-N in Thunderbird, or Spark's compose button.
- Type the recipient and subject by hand.
- Click into the body so the cursor is blinking there.
- Press the Microphone key or your Dictation shortcut. Speak the greeting, then say "new paragraph", then the message.
- Stop with the Microphone key or the shortcut. Read the email, then send.
Setup is in How to use voice to text on a Mac. See the Mac dictation shortcut guide, Mac dictation commands and Mac Dictation not working. If you use Apple Mail, see How to dictate in Apple Mail.
When is a push-to-talk dictation app worth it?
Email is where many people first want voice: long replies, many a day, often the same phrases. A hold-to-talk key that works in every mail app, plus voice snippets for phrases you repeat, is the case for a dedicated app.
SuprFlow is one example. It is a menu-bar app for Apple Silicon Macs on macOS 14 or later. Hold the Fn key, speak, release, and it pastes the text into whichever text field has focus. Speech recognition runs on the Mac with an on-device model; optional cloud formatting sends transcript text, not audio, to the provider you pick. Default formatting is local cleanup of punctuation, capitalization and numbers. It costs $125 for lifetime access on up to 5 Macs you own, with no subscription and a 7-day refund on a first purchase (as of 3 October 2026).
Because it pastes at the cursor, it should work in an ordinary text field; test it in a draft to yourself in each app with a harmless sentence. It transcribes what you say; it does not rewrite it into a new draft the way Superhuman's Write with Voice does. We have not run a controlled benchmark against Apple Dictation.
Which route should you use?
| App's own voice feature | Apple Dictation | System-wide app (SuprFlow as the example) | |
|---|---|---|---|
| Superhuman on a Mac | Write with Voice is documented for mobile | Yes | Should work; test first |
| Spark on a Mac | Siri dictation is documented for iOS 27 | Yes | Should work; test first |
| Thunderbird | None documented | Yes | Should work; test first |
| Exact words or AI rewrite | Superhuman: AI rewrite | Exact words, with punctuation | Exact words, with local cleanup |
| Cost | Superhuman: all plans | Free with macOS | $125 once |
| Best for | Spoken outlines on a phone | Occasional emails | Many emails a day on a Mac |
What goes wrong when dictating email?
- Send shortcuts. Thunderbird lists Command-Return as "Send Message Now" and Command-Shift-Return as "Send Message Later" (Keyboard shortcuts). Keep your hand off the Command key while you dictate.
- Single-key shortcuts in Superhuman. Superhuman uses keys like C to compose and / to search (Keyboard Shortcuts). Click into the body before you speak so text is not treated as commands.
- Paragraphs vs line breaks. In Thunderbird, Return "inserts a paragraph break in paragraph format mode", and Shift-Return inserts a line break. Apple says "new line" equals pressing Return once, so it starts a paragraph there.
- Recipients. Speech recognition is poor at email addresses. Type or pick recipients.
- Silence. Apple says Dictation stops after 30 seconds without speech.
What should you check before you send?
- To, Cc and Bcc, and which account you are sending from.
- The subject line.
- Names, figures, dates and times.
- Every "not", "no" and "never".
- Attachments you mentioned.
- The sign-off and signature.
On privacy: Spark says "The content of the emails you send and receive is stored on the server of your email account," and that features such as Send Later, shared drafts and templates use Spark's servers (Spark Email Privacy). Thunderbird stores messages and settings in a profile folder on your Mac (Profiles), alongside whatever your mail server keeps. See where dictated text goes after insertion.
Questions people ask
Does Superhuman have dictation on a Mac?
Superhuman documents Write with Voice in its iOS and Android apps, and says it is not traditional dictation. On a Mac, use Apple Dictation in the compose window.
Can I dictate email in Spark on a Mac?
Yes, with Apple Dictation in the message body. Spark documents Siri-based dictated replies for iOS 27.
Does Thunderbird have voice typing?
Mozilla's Thunderbird help does not describe one. Apple Dictation types into Thunderbird's compose window.
How do I stop Thunderbird sending a half-finished email?
Avoid Command-Return while dictating; Thunderbird uses it to send the message now.
Related guides
- How to dictate in Apple Mail on a Mac
- How to dictate an email in Outlook on a Mac
- Voice typing in Gmail on a Mac
- Voice to text for emails on a Mac
- Voice snippets on a Mac
- How to use voice to text on a Mac
Sources
- Superhuman Help — Write with AI
- Superhuman Help — Keyboard Shortcuts in Superhuman Mail
- Spark — Spark on iOS 27
- Spark — Spark Email Privacy: Everything you Need to Know
- Mozilla Support — Keyboard shortcuts in Thunderbird
- Mozilla Support — Profiles: where Thunderbird stores your messages
- Apple — Dictate messages and documents on Mac