mail-agent is a local mail, calendar, and contacts app that works with Fastmail. It is made for people who want one tool for email, events, and address book access on Windows.
Use it to:
- check email from Fastmail
- view and manage calendar events
- access contacts in one place
- connect with agent tools through MCP
- keep data on your own computer
Visit this page to download mail-agent for Windows:
Download mail-agent from Releases
On the Releases page, look for the latest Windows file. It may end in .exe or come as a .zip file.
If you see a .zip file:
- Download the file
- Open the zip folder
- Move the app files to a folder you can find later
- Open the app file inside the folder
If you see a .exe file:
- Download the file
- Double-click the file
- Follow the on-screen steps
Before you start, make sure your Windows PC has:
- Windows 10 or Windows 11
- Internet access
- A Fastmail account
- Enough space for the app and its local data
- Permission to run downloaded apps
For the best results, keep your browser open while you set up the app the first time.
Follow these steps in order:
- Open the Releases page
- Download the latest Windows file
- If Windows shows a security prompt, choose the option that lets you keep the file
- If the file is zipped, extract it first
- Open the app from the folder or double-click the installer
- Wait for the app to finish starting up
- Leave the app open while you complete setup
If Windows blocks the file, check that you downloaded it from the Releases page linked above.
After the app opens, you will need to connect your Fastmail account.
- Open the app settings or first-run screen
- Enter your Fastmail email address
- Sign in with your Fastmail account
- Allow access to mail, calendar, and contacts
- Wait for the first sync to finish
Once the sync ends, your mail, events, and contacts should appear in the app.
mail-agent helps you work with:
- email folders and messages
- calendar events and reminders
- contact lists and address details
- local tools that use MCP
- workflows that combine mail and calendar data
Common uses:
- read and sort new mail
- check meeting times
- look up a person’s contact details
- keep calendar and mail in one place
- connect an agent to your Fastmail data
mail-agent runs on your computer and connects to Fastmail services.
It uses:
- JMAP for mail data
- CalDAV for calendar data
- CardDAV for contacts
- MCP for local agent access
You do not need to know those terms to use the app. They are the parts that let the app talk to your Fastmail account and other tools.
If the app does not start:
- try right-clicking the file and choose Run as administrator
- check that Windows did not move the file to quarantine
- make sure you downloaded the latest release
- move the app to a simple folder, such as
C:\Apps\mail-agent
If your account does not connect:
- check your email address
- make sure your internet is working
- sign in again from the setup screen
- confirm that Fastmail access is allowed in your account
If mail or events do not appear:
- wait a few minutes for the first sync
- refresh the app
- sign out and sign back in
- check that your Fastmail account has the data you expect
If you use a zip file, place the app in a folder like this:
C:\Apps\mail-agentC:\Users\YourName\Downloads\mail-agentC:\Tools\mail-agent
Keep the files in one place so you can find the app later.
On the Releases page, you may see files such as:
- Windows installer
- portable zip package
- release notes
- checksum file
If there are several files, choose the one that says Windows and matches the file type you want.
This app is for people who want:
- Fastmail-based mail and calendar access
- a local app that stays on their computer
- a simple way to connect mail data to agent tools
- one place for email, calendar, and contacts
It fits users who want a clean setup and direct control over their data.
caldav, calendar, carddav, codex, codex-plugin, contacts, email, fastmail, jmap, mcp, typescript