For assistants

For assistants: three inboxes, three voices

Most email tools assume one person writing as themselves. That is not the job. If you are an executive or virtual assistant, you write as yourself, and as your principal, and often as a second principal, and each of them has a register you have spent months learning by hand.

MailTwin learns voice separately for every mail account. If Apple Mail carries your address and two executives' addresses, it builds three separate voices from three separate sets of sent mail, on the Mac itself. Nothing is shared between them. Switching mailbox switches the voice.

As far as we know, nothing else does that. For most people it is a footnote. For this job it is the whole thing.

How it works

Select the message in Apple Mail, type the points the reply needs to make — "Thursday works, papers attached, apologies to Jean" — and MailTwin writes the finished email into the reply window: greeting, every point in full sentences, sign-off, in that account's learned voice. You read it, change what you want, and send it. It never sends on its own.

It also summarizes long threads, pulls out action items, translates, and improves a draft you have already written, including inside Mail's own compose window.

The part your principal will ask about

Correspondence you handle is not yours to hand to a third party, and that objection deserves a real answer rather than a privacy badge.

MailTwin has no server. There is no MailTwin account, and there is nowhere for your mail to be sent even if we wanted it. You choose the AI engine from eight. Two of them, Apple Intelligence on macOS 26 and later, and Ollama, run on the Mac itself, so the message is never transmitted at all. With a cloud provider, the request goes from the Mac straight to that provider under a key you supply and can revoke. Voice learning reads sent mail locally and stores its samples locally, under your own user account.

If your organisation's answer is "no cloud AI at all", the on-device engines are a complete answer, not a degraded mode.

What it does not do

It does not triage, file, or answer anything by itself. It has no autonomous mode. It is macOS 13 or later only, Apple Mail only, with no iPhone or iPad app, and it needs two macOS permissions on first run, Automation for Mail and Accessibility, which is a few minutes in System Settings and cannot be automated, by Apple's design.

And it will not save you much if your replies are mostly one line. The tool earns its place on the messages that take a paragraph, which for this job is most of them, but it is worth knowing which half of your inbox it is actually for.

For associations and assistant networks

If you run a body for administrative professionals and want your members to look at this, write to [email protected] and we will send licences for the office to use for a fortnight, with no conditions and nothing expected in return. Endorsements are not asked for and not implied. MailTwin is made by Smilodon AS, a one-person company in Norway, and the person who answers that address is the person who writes the code.

Common questions

Can MailTwin write in more than one person's voice?

Yes, and that is the point of it. Voice is learned separately for every mail account. If Apple Mail carries your own address and two executives' addresses, MailTwin builds three separate voices from three separate sets of sent mail, and nothing is shared between them.

Is my executive's mail sent to a third party?

That is your choice. Two of the eight AI engines, Apple Intelligence and Ollama, run on the Mac itself, so the message is never sent anywhere. With a cloud provider the request goes from the Mac straight to that provider under your own key. There is no MailTwin account and no MailTwin server in the path.

Does it send anything automatically?

No. It drafts. Every message is a draft you read, edit and send yourself. There is no autonomous mode and no scheduled sending.

Does it work with Outlook or Gmail accounts?

It works with whatever Apple Mail carries, which includes Exchange, Microsoft 365, Gmail, iCloud and IMAP accounts. It is the Mail app it attaches to, not the mail provider.

What does it cost?

A one-time licence with a 30-day full trial, no card required to start. There is a five-licence pack for a team.

Try it on a real week

Thirty days, every feature, no card.

Download MailTwin →

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