package simplemail import ( "encoding/json" "net/mail" ) type FromAddress struct { *mail.Address } var _ json.Unmarshaler = &FromAddress{} func (f *FromAddress) UnmarshalJSON(b []byte) error { var a string err := json.Unmarshal(b, &a) if err != nil { return err } address, err := mail.ParseAddress(a) if err != nil { return err } f.Address = address return nil }