Automations: when this happens, do that — Send the record's own file, and choose who replies
A step that takes a file, such as saving to Google Drive or OneDrive or attaching one to an email, offers a choice under the file's box: A web address, or The newest file in one of the record's Attachment fields. The newest file is the one added last, usually the PDF that a Generate a PDF step earlier in the same run has just made. If the field is empty, the step fails and names the record that had no file, and nothing is sent.
The Postmark, Resend, SendGrid and Outlook email steps take a Reply to address, and it can be a token: {{record.owner.email}} sends answers to whoever owns the record. Google Drive saves only into folders RowFold made, so Create a Google Drive folder makes one per client or job and hands back its id to save on the record. OneDrive takes a folder path such as Clients/{{record.client}} and makes any folder that is missing.
For a Teams channel message, paste the channel's link from Get link to channel into Channel ID. RowFold reads the team and the channel out of it, so Team ID can stay blank.