diff --git a/api.js b/api.js
index dc345789..43f1905b 100644
--- a/api.js
+++ b/api.js
@@ -21,6 +21,7 @@ const os = require('os');
 const util = require('util');
 const ObjectID = require('mongodb').ObjectID;
 const tls = require('tls');
+const Lock = require('ioredfour');
 
 const acmeRoutes = require('./lib/api/acme');
 const usersRoutes = require('./lib/api/users');
@@ -498,6 +499,11 @@ module.exports = done => {
 
     server.loggelf = message => loggelf(message);
 
+    server.lock = new Lock({
+        redis: db.redis,
+        namespace: 'mail'
+    });
+
     acmeRoutes(db, server);
     usersRoutes(db, server, userHandler);
     addressesRoutes(db, server, userHandler);
diff --git a/imap.js b/imap.js
index ddd86ea1..ab7eab63 100644
--- a/imap.js
+++ b/imap.js
@@ -121,7 +121,7 @@ let createInterface = (ifaceOptions, callback) => {
 
     server.lock = new Lock({
         redis: db.redis,
-        namespace: 'imap'
+        namespace: 'mail'
     });
 
     // setup command handlers for the server instance
diff --git a/lib/api/messages.js b/lib/api/messages.js
index f94d7007..cbebc31b 100644
--- a/lib/api/messages.js
+++ b/lib/api/messages.js
@@ -172,6 +172,25 @@ module.exports = (db, server, messageHandler, userHandler, storageHandler) => {
 
         if (moveTo) {
             let info;
+
+            let lockKey = ['mbwr', mailbox.toString()].join(':');
+
+            let lock;
+
+            try {
+                lock = await server.lock.waitAcquireLock(lockKey, 5 * 60 * 1000, 1 * 60 * 1000);
+                if (!lock.success) {
+                    throw new Error('Failed to get folder write lock');
+                }
+            } catch (err) {
+                res.status(500);
+                res.json({
+                    error: err.message,
+                    code: err.code || 'LockFail'
+                });
+                return next();
+            }
+
             try {
                 let data = await moveMessage({
                     user,
@@ -188,6 +207,8 @@ module.exports = (db, server, messageHandler, userHandler, storageHandler) => {
                     code: err.code
                 });
                 return next();
+            } finally {
+                await server.lock.releaseLock(lock);
             }
 
             if (!info || !info.destinationUid || !info.destinationUid.length) {
@@ -204,6 +225,7 @@ module.exports = (db, server, messageHandler, userHandler, storageHandler) => {
                 mailbox: moveTo,
                 id: info && info.sourceUid && info.sourceUid.map((uid, i) => [uid, info.destinationUid && info.destinationUid[i]])
             });
+
             return next();
         }