I have found what I believe is a bug in the Base64Encode function in FileMaker. I have been using the encoding to try to send an email message through the gMail API sandbox. Emails must be Base64 encoded and sent in the "raw". However, all the FileMaker encoded emails I have tried to send have come back with an error code, including "message": "Recipient address required". An email encoded in FileMaker returns an error, the identical email encoded on line goes just fine. Attached you will find documentation of my exploration of this problem. My work was done on a Windows 7 platform in FileMaker 16. I checked the encoding on a virtual Mac using FileMaker 17, and a quick glance leads me to believe this problem has not been corrected.