Brett - I don’t think you can make that generalization. There are many ways of sharing files besides via email.
You should be able to construct a system that allows the user to download any of the pdf reports on demand. This might be generating the report on the fly, accessing a “presaved” report from the database (Carl’s BLOB suggestion), or accessing the pdf as a file on the server. Let me comment on each.
Generating report on the fly - This is typically the most flexible way of delivering the report for your users. It only relies on the data being in the database for that time period. Through clever bindings the user can select time periods, options, etc and have the report created for them. They can then save it locally as a pdf.
Saving reports to database - Here you generate periodic reports and save them to your SQL database as a BLOB. This is similar to using the database as your file system. This approach tend to be operating system independent and very secure (as is #1).
Writing to files, then accessing those files - This is usually done by reading and writing to network shares, which can be done in Ignition, but goes outside of the scope of the system (relies directly on operating system networking). In your case, I wouldn’t recommend it over the Internet.
3a. You might be able to write files locally to a place where the web server portion of the gateway publishes the files, then access it via a web browser. You could even have the system email a link out.
I recommend investigating options #1 and #2 first.