I responded to an invitation to submit a proposal this morning they've just replied that they can't open my attachments to see the samples I sent and asked me to email them. This happens frequently. What am I supposed to do now that we aren't allowed to do this? Tell her I can't have your email address and can't send them even though the system isn't working? I'm just going to leave it for now because I have no clue what to do.
Upwork is not a file transfer tool. I don't rely on it for that, and neither should you.
FTP is a good option, and is explicitly allowable even after June 26 when new policies take effect.