PDF file preview support require using HCL verse.

HCL Verse 3.1 allows the users to preview file attachments in emails using the Domino POI service. This is a good option for previewing attachments when Connections is not integrated.

https://help.hcltechsw.com/verse_onprem/3.1/admin/enabling_file_preview_using_domino1202.html

But using this feature we can only preview MS documents.

Using Domino POI service

If your administrator has configured the server to use the Domino POI file viewer service, you are able to preview the contents of Microsoft Office documents and images by clicking on the attachment. From the viewer, you are able to download that file. For more information.

Using Connections

If your administrator has integrated HCL Connections, you are able to preview the contents of a spreadsheet, document, presentation, PDF, and an image. From the viewer, you are be able to download that file or upload that file (to Connections).

https://help.hcltechsw.com/verse_onprem/3.1/user/preview_attachments.html

Can we get feature which will help to preview all types of attachments such as txt, pdf etc..