What features are on your roadmap?

Please visit the Roadmap to see what we have planned for Mimestream. You can click on features, indicate their priority, and sign up for email updates about them. You can also submit your own ideas, too!

Is this app coming to the Mac App Store?

Yes. Once v1.0 is released, the app will be made available on the Mac App Store.

Why can't this app run on older OS versions?

Mimestream requires at least macOS Catalina because it makes use of new APIs and capabilities, such as SwiftUI and Combine. By using SwiftUI when possible, we can re-use more code with a future iOS version of the application and release that version sooner.

Mimestream intends to showcase the best that the Mac has to offer, and new versions will generally require the latest version of macOS (allowing for a breathing period for some bug-fixing software updates to be released by Apple).

Have you updated for Apple Silicon / M1?

Yes, Mimestream has been fully updated to be a universal binary. It runs natively on either Intel or Apple Silicon Macs.

What happens if I stop using Mimestream?

You can continue to use Gmail normally. Your email remains on the Gmail servers, and any changes you make in Mimestream are synced back to Gmail as soon as a network connection is available. No Mimestream-specific labels are added to your account.

Is there an iOS version?

macOS is currently the only supported platform. A version for iOS (and iPadOS) is something we're planning to make in the future, but the focus will be on macOS for some time. See this feature on our roadmap to upvote, provide additional input on, and sign up for updates about this.

Does Mimestream support services besides Gmail?

Mimestream currently only supports Gmail. Future support for other services is planned, including Microsoft 365 / Outlook, services that support IMAP, and services that support JMAP. See the ideas tab to roadmap to upvote support for these services.

Will Mimestream be translated/localized for other languages?

Yes, Mimestream plans to localize for other languages as it gets closer to a 1.0 launch. If you are able to volunteer to help translate into your native language, please email hello@mimestream.com!

App Preferences

How do I change the message text size permanently?

Message text size can be changed in the app's preferences. From the menus, select Mimestream, then Preferences, and on the General tab, you should see a Text Size slider that you can adjust.

How do I use Gmail shortcuts? Or Apple Mail shortcuts?

Gmail shortcuts can be activated in Preferences. From the menus, select Mimestream, then Preferences, and on the General tab, there is a "Keyboard Shortcuts" preference that can be switched to the Gmail or Apple Mail shortcut set.

Improvements to the Gmail shortcut set are planned in the short term. Currently, some key shortcuts such as "G,I" and "V" do not work.

How do I make Mimestream the default email client?

Option 1: Open Apple Mail to change the default email client, following the instructions on Apple's support site. You will be required to add an account first, if you haven't.

Option 2: Download Microsoft's SetDefaultMailApp tool and set com.mimestream.Mimestream as the default.

Unfortunately, Mimestream cannot offer this option in the app. Mimestream is a sandboxed application targeted for the App Store, and macOS security restrictions currently prevent sandboxed applications from changing the default email client.

Common Issues

The app keeps crashing, what should I do?

First, we would love to get some diagnostics from you. Open Terminal, and run the following command:

Please send the output (on your Desktop) to bugs@mimestream with a brief description of the problem.

Then, you may delete Mimestream's container to get the app running again. In Terminal, run the following command:

rm -rf ~/Library/Containers/com.mimestream.Mimestream
You'll have to set up all of your accounts and preferences from scratch.

I'm not getting any notifications for new email!

Please check to make sure that Notifications are enabled in system preferences. Open System Preferences, click Notifications, select Mimestream from the list, and ensure that notifications are enabled.

Contact Us

How do I suggest a feature or improvement?

To suggest a feature, please visit our Roadmap. If you see the feature you'd like already listed, you can click on it to indicate the priority to you and sign up for updates about it. If you don't see it, please don't hesitate to click the Submit Idea button! Feature development is prioritized based on user demand, so your feedback and suggestions are greatly appreciated!

What do I do if I've hit a bug?

Please use the in-app Help > Report a Bug… menu item, or email bugs@mimestream.com to report a bug.

Bug reports are extremely helpful and your feedback is very much appreciated! We prioritize bug fix order based on a combination of severity, number of user reports, and our product judgement.

How do I contact support?

Please e-mail support@mimestream.com to contact support.

Privacy and Security

Where is my email data stored?

Mimestream follows the model of a traditional e-mail client: a cache of your recent messages are stored on your device, and the originals remain on the Gmail server. Mimestream communicates directly from your device to Google's APIs, without using an intermediary server. In addition, your account's access tokens stay on your device.

Mimestream's use of information received from Gmail APIs will adhere to Google's Limited Use Requirements.

Where are my email credentials stored?

When you grant Mimestream access to your Google account, Mimestream receives tokens and stores them in your Mac's keychain. Your Google account's password is not stored in the Keychain by Mimestream, and isn't even seen by the Mimestream app during the Oauth authentication flow.

Can you read my email?

No. Mimestream is a local app that stores your data and access tokens directly on your device. Mimestream does not run any servers with access to your email.

How is push handled?

Mimestream makes a direct IMAP connection from your Mac to imap.gmail.com on port 993, and then uses the RFC 2177 IDLE extension to listen for new message notifications. Notifications are only received while Mimestream is running.


How much does this app cost?

Pricing has not been set yet, and won't be determined until closer to 1.0.

Why will this app cost money?

Mimestream's core business is developing high quality e-mail software. Instead of monetizing your e-mail data for advertising or market research purposes, Mimestream generates revenue by charging for our software.

Do you offer an enterprise site license?

Yes! A site license is a great way to offer Mimestream to all of your employees and boost their productivity, while being confident in the secure handling of your organization's email data and credentials.

Please contact us with how many seats you'd like, and we'll get back to you as soon as Mimestream is available for site license purchase (after reaching 1.0)! In addition, if you have any special requirements or wishlist items, we'd love to hear from you!