diff --git a/backend/bin/www b/backend/bin/www
index f8e47c7..7cf50d9 100644
--- a/backend/bin/www
+++ b/backend/bin/www
@@ -8,11 +8,20 @@ const app = require('../app');
 const debug = require('debug')('backend:server');
 const http = require('http');
 const mongoose = require('mongoose');
+const schedule = require('node-schedule');
+const {findAllTeams, getUsersCommits, getUsersEmail, sendMails} = require('../src/services/mail/mailAutoSender');
 
 mongoose.connect(process.env.DATABASE_URL)
 .then(res => console.log("MongoDB Connected"))
 .catch(err => console.error(err));
 
+const autoMailScheduler = schedule.scheduleJob('*/5 * * * * *', async () => {
+  const teamIds = await findAllTeams();
+  const users = await getUsersCommits(teamIds);
+  const userEmails = await getUsersEmail(users);
+  await sendMails(userEmails);
+});
+
 /**
  * Get port from environment and store in Express.
  */
diff --git a/backend/package.json b/backend/package.json
index 9accb41..6c86553 100644
--- a/backend/package.json
+++ b/backend/package.json
@@ -15,6 +15,7 @@
     "express-session": "^1.17.2",
     "mongoose": "^6.0.7",
     "morgan": "^1.9.1",
+    "node-schedule": "^2.0.0",
     "nodemailer": "^6.6.5",
     "passport": "^0.4.1",
     "passport-github": "^1.1.0"
diff --git a/backend/src/models/user.js b/backend/src/models/user.js
index 82d2515..6714fa9 100644
--- a/backend/src/models/user.js
+++ b/backend/src/models/user.js
@@ -5,7 +5,6 @@ const Schema = mongoose.Schema;
 const userSchema = new Schema({
         nickName: String,
         email: String,
-        teamIds: Array,
         githubId : String,
         accessToken: String
 });
diff --git a/backend/src/services/mail/mailAutoSender.js b/backend/src/services/mail/mailAutoSender.js
new file mode 100644
index 0000000..985c702
--- /dev/null
+++ b/backend/src/services/mail/mailAutoSender.js
@@ -0,0 +1,84 @@
+const Team = require("../../models/team");
+const User = require("../../models/user");
+const { getCommitCountOfTeam } = require("../github");
+const nodemailer = require('nodemailer');
+
+const findAllTeams = async () => {
+    try{
+        const teams = await Team.find({});
+        const teamIds = teams.map(el => el._id.toString());
+        return teamIds;
+    }
+    catch(err){
+        console.error(err);
+    }
+};
+
+const getUsersCommits = async (teamIds) => {
+    try{
+        const users = [];
+        for(let i = 0 ; i < teamIds.length; i++){
+            const commits = await getCommitCountOfTeam(teamIds[i]);
+            users.concat(commits);
+        }
+        return users.filter(el => parseInt(el.commit) === 0).map(el => el.userId);
+    }
+    catch(err){
+        console.error(err);
+    }
+};
+
+const getUsersEmail = async (users) => {
+    try{
+
+        const userIds = [];
+        for(let i = 0; i < users.length; i++){
+            const user = await User.find({githubId:`${users[i]}`});
+            userIds.push(user.email);
+        };
+        return userIds;
+    }
+    catch(err){
+        console.error(err);
+    }
+};
+
+const sendMails = async (userIds) => {
+    try{
+        const email = process.env.GMAIL;
+        const emailPw = process.env.GMAILPW;
+
+        let transport = nodemailer.createTransport({
+            service: "gmail",
+            auth:{
+                user: email,
+                pass: emailPw
+            }
+        });
+
+        userIds.forEach(el => {
+            
+            let mailOptions = {
+                from: email,
+                to: el,
+                subject: "1일 1커밋 운동 참여 독려",
+                html:`
+                <h1> 1일 1커밋 운동에 참여하세요! </h1>
+                <p>자라나라 잔디잔디!</p>
+                <p>아직 오늘이 가지 않았습니다! 커밋을 보내 잔디밭을 키워보세요!</p>
+                `
+            };
+
+            transport.sendMail(mailOptions, async (error, info) => {
+                if(error) throw new Error("메일을 보내는 데 실패하였습니다.");
+            });
+        });
+
+
+    }
+    catch(err){
+        console.error(err);
+    }
+};
+
+module.exports = {findAllTeams, getUsersCommits, getUsersEmail, sendMails};
\ No newline at end of file
diff --git a/backend/src/services/team/team.js b/backend/src/services/team/team.js
index 41785bc..fd372f6 100644
--- a/backend/src/services/team/team.js
+++ b/backend/src/services/team/team.js
@@ -2,6 +2,10 @@ const Team = require("../../models/team");
 
 const createTeam = async (req, res, next) => {
     try{
+        
+        if(req.body.password === undefined) req.body.password = null;
+        req.body.password === null ? req.body.isLocked = false : req.body.isLocked = true;
+        
         const result = await Team.create({...req.body});
         await res.status(201).json({
             code: '2001',
@@ -98,6 +102,7 @@ const enterTeam = async (req,res,next) => {
         const teamId = req.query['teamId'];
         const userId = req.query['userId'];
         const team = await Team.findById(teamId);
+        if(team.password !== null && team.password !== req.body.password) throw new Error("비밀번호가 일치하지 않습니다.");
         const userIds = [...team.userIds];
         userIds.push(userId);
         team.userIds = userIds;