It’s hard to know what to tell you because you haven’t said what the problem is. Are you getting an error when you try to send? How does it fail? Do you get an error, or does it just not get there? Did you check spam?
Also, Meta is very helpful, and everyone helps where they can, but you have to first help your self. Asking broad questions without trying to read and understand past answers or research a solution won’t work well here, so I’ll suggest sharing more details and rewording your question, also based off what your problem is, do try to use the search button and read through past answers, we are all here to help each other help ourselves