Your donors or participants who use Gmail are receiving system emails regarding registrations and orders from "Unknown Sender". You wish to include your event name, so that constituents will open the emails.
Emails should appear as being from the Event Name that you enter in Events -> Settings. However, if you are including any special characters in your event name, Google is likely removing the name due to the special character. Try using an event name that only includes letters and numbers.
If you must include special characters in the event name, or if you have tried removing the characters but the issue has not been resolved, try adding quotation marks around your Event Name from Events -> Settings. This causes Google to read it as a string, instead of interpreting the punctuation as code.
Please note that the quotes will now appear on your website pages if the event name is auto-populating anywhere. You can fix this by going to Website-> Pages and clicking Edit next to the page you want to change. Then remove the Event Name Snippet (the little piece of code that pulls in the Event name automatically) and instead type out the event name and format as desired.