Integration of WebMail Pro with Nextcloud allows users to access their email accounts from within Nextcloud interface, so WebMail Pro acts and looks like a native application there.
IMPORTANT: This app does not install the product itself, it's assumed that webmail application is already installed on the same server where you have Nextcloud set up. The scenario of running Webmail and Nextcloud on different servers is supported as well.
In Apps screen of Nextcloud, search for Afterlogic, and click "Download and enable" button. Alternately, you can download the application and extract it into
apps/ directory on server directly. Note that the latest version only supports Nextcloud 22, if you're on version 19 through 21, download the previous version.
Under Settings > Administration > Additional settings, specify URL of WebMail installation you’ll be accessing, and select authentication method used. The recommended option is Web API, but it'll only work if Nextcloud and WebMail Pro are in the same domain.
If you have Nextcloud and WebMail Pro in different domains or on different servers, you'll need to select POST method. For this to work, set AllowPostLogin to true in data/settings/modules/Core.config.json file of WebMail installation (it's less secure compared to Web API but it's the only way of sending credentials to remote server or other domain).
Configuring by users
Under Settings > Personal > Additional settings, specify email address and password of your email account. Clicking "Mail" button in Nextcloud top bar should log you into that email account automatically.
Source code of this app is available on Github.
If you have any questions or encounter any issues using WebMail within ownCloud, please feel free to open a ticket at the issue tracker. Thanks!