are you sending a PDF (select print as pdf) of your tax return or the tax file (.tax2023)? you should be able to save a PDF of the tax return to your desktop to e-mail to your accountant. There are obvious risks in doing this. My firm would encrypt the tax return PDF file and send it in an email to the taxpayer. then a while later it sent a second e-mail with the code to enable the taxpayer to open the encrypted file.
if you are still having problems, it would seem the only other way would be to print it out and mail it.
