I'm sorry that you're having trouble sending your files with Adobe Send. TIFF files are definitely a supported format. (The file formats that Adobe Send supports are listed in the Sending Files section of this document: Adobe Send FAQ.)
If you wouldn't mind answering these questions, we can try to get to the bottom of this:
I look forward to hearing back from you.
Thank you for the fast response!
my tiff file is 100mb I shoot large and my client demands the larger format tiff. I get an error upon upload completion…maybe it’s too large?