Hey Apeksha, this activity is used to retrieves mail messages from IBM Notes. It works with IBM Notes only and comes with UIPATH.MAIL.ACTIVITIES package. It takes MailFolder as input. MailFolder is the folder from which the messages are to be retrieved. In output, it returns Messages by default.
Though, you can check GetAttachments checkbox in properties, to specify whether to retrieve the attachments in the email message. It is basically the same as Get Outlook mail activity, as it returns a list of emails you can then handle the very same way. The only difference is that it interacts to the Lotus/IBM client instead of the Outlook client