Gmail says virus detected for some of my PDFs how do I correct this?

If Gmail is detecting a virus in your PDF attachments, it is likely because the file has been infected. In this case, you should not try to open or download the file, as it could harm your computer or device. 

If you believe that the PDF file is not infected and is a false positive, you can try the following:

1. Scan the file for viruses using a reputable antivirus software or online virus scanner.

2. Compress the file into a zip file and then attach it to your email. Gmail may not detect the virus if it is inside a compressed file.

3. Upload the file to a cloud storage service, such as Google Drive, and then share the file with the recipient using a shareable link.

If none of these options work, you should contact the sender of the file and ask them to send the file again, or to send it using a different method.