Hi sleep
Thanks for your post and Welcome to the Community Forum.
Generally, when this happens, it is due to one of the following reasons: Documents are bigger than 10 MB in size, or Documents are not in one of these formats: PDF, JPG, JPEG, TIFF, TIF, or PNG.
Therefore, please check this with the supplier and if they have emailed the document in the correct size and format, get them to email the document directly to your business/personal email address (as a test) and then check if you can forward that document to the In Tray email address. This would help in troubleshooting. If the issue is with the document or if In Tray is not recognizing the supplier's email address.
Please let me know how you go.
Please feel free to post again. I'm happy to assist you further.
If my response has answered your inquiry please click "Accept as Solution" to assist other users find this information.
Cheers,
Cel