How MICA helps with your mail
MICA is the Ostrae assistant. In Ostrae.email it works on the message you selected or the draft you are writing, and only when you ask.
Updated October 2026 · Describes the product as it is today.
What MICA can do
- Summarize the selected message.
- Suggest a reply to the selected message.
- Rewrite your draft in the composer.
Open a message or the composer and choose Ask MICA. Answers can be in English or Deutsch.
You keep the final word
A suggestion is shown as text first. Nothing is inserted until you choose Insert into draft; a reply suggestion then opens a reply you can edit. A rewrite replaces your draft only after you insert it, and Undo MICA edit brings the previous text back. MICA cannot send mail. AI suggestions can contain mistakes, so read them before you use them.
What is shared, and when
Only the selected message or the current draft is shared, and only when you click an action. That text is sent to Google Vertex AI on an EU model endpoint for that one request. The website does not store an AI history. The connection to Google uses short-lived federated credentials instead of stored keys.
Daily limits
Each person can make 20 MICA requests per day, and there is a shared daily limit across all users. Failed model attempts count toward the limits. When a limit is reached, MICA says so and your mail stays untouched.
MICA Desktop
If you use MICA on Windows, you can connect it to this browser in Settings → MICA Desktop:
- Turn on desktop integration.
- Choose Get connection code. The code is private and valid for five minutes.
- Paste it in MICA under Settings → Connect websites.
The connection is tied to the browser session that created it; signing out or disconnecting ends it. While MICA Desktop is connected, the web assistant steps aside, and Use web MICA instead switches back. You still share only the message or draft you choose; the shared context is encrypted, available for two minutes and used once. Nothing from your mailbox is shared automatically.