Thanks for sharing your findings with using QuickBooks Online's Receipts feature. It's awesome that you're checking out how it works to take advantage of the option to easily add transactions to your account from a receipt image.
The format of the file name can definitely play a role in how the system reads the file and special characters can affect whether the image uploads at all. I recommend removing the underscores from file names to ensure you're able to upload into the Receipts feature.
I know that has the potential to be a lot of work, especially if the file name defaults to have an underscore when you create it. In light of that, I encourage you to submit feedback about this by clicking the Give feedback button on the Receipts page in QuickBooks. Here's another way you can leave feedback about any feature you'd like or would like to see in the program: How do I submit feedback?
Have a great rest of your day.
The problem is - I have rules setup within my mailbox to automatically forward emails to [email address removed] in an attempt to automate the process. If the vendor sends an invoice with an underscore, I get an error every time. I now have to find that e-mail, download the attachment, rename it, and reforward it.
I've noticed the online upload does not have this problem. I can upload files through the web interface with an underscore without issue.
Thanks for the further details. I'm glad to hear that you're able to directly upload without any issue even when there's an underscore in the file name. It sounds then like the issue is with how the system reads the file names from the emails that are being sent.
I can appreciate wanting to use as much automation as possible to cut down on the time spent inputting data into your books manually. Please feel free to share this kind of information in your feedback to the product development team via the method I mentioned in my initial response. Your feedback lets us know how you'd like to manage your books and what changes we can make to continue to enhance what QuickBooks has to offer.