Supported email clients for Microsoft 365 (with Exchange Online)¶
This article outlines the email clients that are compatible with RG Email Sidebar and Sync Engine for Microsoft 365 (with Exchange Online). It includes details on supported versions of Outlook for Windows, Mac, mobile, and web, as well as browser compatibility.
Important
Using unsupported or outdated software versions can lead to performance issues, security vulnerabilities, and reduced functionality for RG Email Sidebar and Sync Engine. To ensure smooth and secure operation, always use supported software versions and upgrade before the end of support.
Subscription-based and web-based Outlook clients¶
| Email client | Support for RG Sync Engine | Support for RG Email Sidebar | Supported by Microsoft |
|---|---|---|---|
| Microsoft 365 Outlook (Windows) | Full | Full | Continuously supported with subscription |
| Microsoft 365 Outlook for Mac | Full | Full | Continuously supported with subscription |
| Outlook on the web | Full | Full* | Continuously supported |
*RG Email Sidebar is fully supported in Outlook on the web, but its performance depends on the browser that is used to access it. For the details about browser support, see this section.
Outlook clients with perpetual licenses (Windows)¶
| Email client | Support for RG Sync Engine | Support for RG Email Sidebar | Supported by Microsoft |
|---|---|---|---|
| Outlook LTSC 2024 (Windows) | Full | Full | Supported until October 9, 2029 |
| Outlook LTSC 2021 (Windows) | Full | Full | Supported until October 13, 2026 |
| Microsoft Outlook 2024 (Windows) | Full | Full | Supported until October 9, 2029 |
| Microsoft Outlook 2021 (Windows) | Full | Full | Supported until October 13, 2026 |
| Microsoft Outlook 2019 (Windows) | Full | Compatible | Supported until October 14, 2025 |
| Microsoft Outlook 2016 (Windows) | Full | Compatible* | Supported until October 14, 2025 |
*Perpetual license versions of Outlook 2016 or earlier do not support Sidebar pinning.
Important
In June 2022, Microsoft ended support for Internet Explorer 11 on most Windows 10 versions. Some editions of Outlook 2016 and 2019 still rely on Internet Explorer to render add-ins, making them incompatible with RG Email Sidebar. For more details, see Internet Explorer end of support.
To ensure full compatibility, we strongly recommend upgrading to:
- Microsoft 365 Outlook (subscription-based).
- Outlook 2021 or later (perpetual license editions).
Outlook clients with perpetual licenses (Mac)¶
| Email client | Support for RG Sync Engine | Support for RG Email Sidebar | Supported by Microsoft |
|---|---|---|---|
| Outlook LTSC for Mac 2024 | Full | Full | Supported |
| Outlook LTSC for Mac 2021 | Full | Full | Supported until October 13, 2026 |
| Outlook for Mac 2024 | Full | Full | Supported until October 9, 2029 |
| Outlook for Mac 2021 | Full | Full | Supported until October 13, 2026 |
Mobile and other clients¶
| Email client | Support for RG Sync Engine | Support for RG Email Sidebar | Supported by Microsoft |
|---|---|---|---|
| Outlook app for iOS or Android | Full | Full | Continuously supported |
| Other desktop or mobile clients connected to Microsoft Exchange that support folders and/or categories (e.g., iOS Mail app) | Full | Not supported | Varies by client |
Note
For detailed information on Microsoft’s support lifecycle, please refer to the official Microsoft Lifecycle Policy.
Supported browsers¶
RG Email Sidebar runs in browsers when used with Outlook on the web. To ensure optimal performance and functionality, please update your browser to the latest version.
| Browser | Support |
|---|---|
| Chrome & Chromium-based | Full |
| Safari (Including iOS version) | Full |
| Android Mobile browser | Full |
| Microsoft Edge | Compatible |
| Firefox | Compatible |
| Opera | Compatible |
| Internet Explorer 11, 10, 9 or lower | Not supported |
Note
For Microsoft Outlook on Windows, ensure the latest version of Microsoft Edge is installed. It is required to render the Sidebar.
Internet Explorer end of support¶
In June 2022, Microsoft ended support for Internet Explorer 11 on most Windows 10 versions. As a result, RG Email Sidebar is no longer supported in the following scenarios:
- Accessing Outlook on the web through Internet Explorer.
- Using desktop versions of Microsoft Outlook (e.g., Office 2016 and 2019 volume-licensed editions) that depend on Internet Explorer 11 to render add-ins.
Volume-licensed editions of Office 2016 and 2019 rely on Internet Explorer 11, which is no longer supported, making RG Email Sidebar incompatible. However, other perpetual license editions of Office 2016 and 2019 may still work under these conditions:
- Without WebView2 installed: Limited compatibility.
- With WebView2 installed: Full compatibility, as these editions use modern rendering technologies instead of Internet Explorer.
Tip
To check your Outlook version and its compatibility, see Microsoft’s guidance on browsers used by Office add-ins.
For full access to RG Email Sidebar features, optimal performance, and modern security, upgrade to:
- Microsoft 365 Outlook (subscription-based).
- Outlook 2021 or later (perpetual license editions).
