I am using the Libre spreadsheet and sending it as an email attachment but finding that the recipients who are not using Libre are unable to open my attachment. Is there a way to save the documents so they can open them when sent as email attachment?
I assume you are saving the spreadsheet as a LO .ODF file. If the users are using MS Excel then save it as .xlsx or .xml, the MS format for Excel.
You can save the document as a PDF with an ODS embedded by choosing the option ‘File → Export as PDF’. That way the receiver does not even need to have an office suite to view the file.
In the PDF export view, you can choose ‘Hybrid PDF (embed ODF file)’ to add the spreadsheet inside the PDF file.
If the receiver has MS Office 2010 or newer, sending an ODS file is fine. Those are supported by Microsoft Office.