????11??????@??????????????

????????abc@def@gmail.com
????????abc@@gmail.com

????12????????????????????

????????abc#def@gmail.com

????13???????????????????

????????a..b@gmail.com
????????a.b@gmail..com

????14?????????????????????

????????a__b@gmail.com
????????ab__c@gmail.com

????15??????????????????л???(????)??????????????

????????____@gmail.com
????????----@gmail.com
????????--__@gmail.com
????????....@gmail.com
????????-_-@gmail.com
????????--..@gmail.com
????????-_.@gmail.com

????16???β?????????~n??????????????

????????abc@abc.def.com
????????abc@abc.def.ghi.com
????????abc@abc.def.ghi.jkl.com

????17???β????????????????

????????abc@123.456

????18???β??е????????????

????????abc@def

????19?????@??????????????

????????abc.def.com

????20????????п????????????(??trim???)

????????abc@gmail.com
????????abc@gmail.com

????21???м???п????????????

????????a b c@gmail.com