Hi guys,
so far in Nextcloud Mail we cannot open an attachment like XLSX, DOCX or any other format that is supported by Collabora directly. This is an open issue for more than 3 years and the workaround to first store the attachment to a Nextcloud folder and then open it from there is a big productivity killer and not on par with other mail clients.
As Christoph Wurst in the Github thread Ability to directly view further attachments from email · Issue #5988 · nextcloud/mail · GitHub mentions this is mainly because the mail attachment file at this initial mail viewing stage is not stored in the Nextcloud File System and Collabora Online can therefore not access it
Could you collaborate with Nextcloud on this and get this fixed please? Maybe you both can get together at the upcoming developer conference and put some heads together how to fix this. I am sure a solution can be found.
Thank you so much !
Thorsten