Today I broke a pcb manufacturer website trying ot upload a zipped project file using my a KiCad nightly build. They said to email them, when I did, I got a bounce message saying:
host aspmx.l.google.com[188.8.131.52] said: This message was blocked because its content presents a potential security issue. Please visit https://support.google.com/mail/?p=BlockedMessage to review our message content and attachment content guidelines.
It took me a few minutes to understand what is happening, eventually I found what I was looking for at the list under "Types you can't include as attachments" and the culprit: .lib
I had a custom footprint in my repository and this is saved as
I did a facepaw.