Mail problem copies of outgoing mail keeps going in trash

New to mac. Set up my email so my gmail acct is tied to Mail. Started using it more the last few days and while I am composing an email I see activity in the activity window like stuff incoming and outgoing like 4-8 emails. Later I opened my trash and found a bunch of stuff in there. The emails I am actually sending are being received but why are there sometimes multiple copies of emails I have sent?. I am not asking that anything sent be put in the trash. Any help would be appreciated.