RMail has a number of different Sending Applications, ( Sending Apps) each designed to work with a corresponding Email platform or service, so pick the RMail application that corresponds with the way you send an Email.
The most popular Sending Apps, the RMail Outlook Desktop plug-in, is downloaded and installed on your computer, Installing the RMail for Outlook app adds a “Send Registered™” button to the mail compose window in Microsoft Outlook. This add-in also works with Office 365 (if you install Microsoft Outlook onto your computer). The button will appear above or next to the traditional “Send” button and allows the user to send RMail messages.
The other RMail Sending Apps are simply extensions or add-ons that can be added to your existing online Email service providers, like Gmail and Outlook Online.
You can also use RMail with its own on-line version, Web-Based RMail, which can be accessed using any internet browser.
Lastly, if you want your own @rmail.com email address, you can sign up for the RMail Inbox is a full-featured, private webmail alternative used in conjunction with Web-Based RMail.
All the Sending Apps can be downloaded from the RPost website here https://www.rmail.com/apps/
The RMail for Outlook Desktop plug-in offers every available feature and is the 'default' application that most of the Help Center guides and articles refer to. The table below shows a quick look at all the different Sending Apps and the features that are available, for additional information and installation requirements, please visit the download page listed above.