Skype for Business may sometimes fail to send attachments.
Lets dive in and see what you’re able to do about this problem.
make a run at convert that file to a different format or manually edit the filename extension.
Contact your admin and ask them to check the file transfer tweaks for your account.
In this case, the recipient should contact their admin for further assistance.
Then, erase the app cache, and ask your IT admin to check your accounts file transfer prefs.
