I am a Mac user. For our camera club submissions we resize our photos to 1920 on the long side and 1080 on the short side, this is equivalent to 16x9. I use PS but am sure it is possible in LR, go to “image” and click on image size and make your changes there, then save as a copy and choose JPEG, when the next dialog box pops up make sure your image is 2mb or less, if it is greater move the slider from 12 down until you get a suitable size. This will not degrade the quality of your image. When you wish to email the image, initiate the email first and then add as an attachment and keep as actual size. Hope this helps.

If your camera club is like mine, there is a size limit on the size of the file/image that is submitted. A full size file is not allowed. Way too much data. They are showing these on a screen in front of the crowd...not printing them out. I am not familiar with the email aspect of LR, but I export the selected image to a jpg with the specific size requirements of my club. (1400 pixels wide by 1280 tall.) I export it into a folder and then send the file via email. There is no need for file sharing or other machinations. The person (volunteer) putting the images together has not enough time in the day to receive the link, download massive amounts of data, then put it into the LR presentation along with all other submitted photos. I am betting that the person receives the files, puts them into LR or similar, for use by the club at the meeting and needs to move on.

As others noted, it is possible that the thing is being sent as an embedded image or something like that...send it as a file..a universally understood file that LR recognizes. Such as "Robins Eggs.jpg."

If you club does not have file size requirements, I can send you ours. They also have a file naming protocol as well which works as well.