It appears you are having difficulty with the pdf file size for the return that is printed. That has been an issue for a few years and here is where you can vote to try to get Lacerte to address that issue. https://proconnect.intuit.com/community/lacerte-tax-idea-exchange/reduce-pdf-size/idi-p/124015

Your file size is HUGE. Rather than e-mail you should likely begin to use a portal to transfer files.  Mozilla Thunderbird recently launched their version https://support.mozilla.org/en-US/kb/filelink-large-attachments