feat: add callback function to mock

pkg/email/mock.go

@@ -6,7 +6,9 @@ import (
 	"net/smtp"
 )
 
-func NewMockMailService() *EmailService {
+type MockCallbackFn func(params ...interface{})
+
+func NewMockMailService(callbackFn MockCallbackFn, params ...interface{}) *EmailService {
 	return &EmailService{
 		auth: smtp.PlainAuth("", "", "", ""),
 		host: "",
@@ -17,6 +19,7 @@ func NewMockMailService() *EmailService {
 			ServerName:         "",
 		},
 		dial: func(hostPort string) (SMTPClientIface, error) {
+			callbackFn(params)
 			return &mockSMTP{}, nil
 		},
 	}