diff --git a/demo/payload.config.js b/demo/payload.config.js
index 0db7c9c9f4..4e81e04cd6 100644
--- a/demo/payload.config.js
+++ b/demo/payload.config.js
@@ -43,6 +43,7 @@ module.exports = {
     },
   },
   email: {
+    transport: 'mock',
     fromName: 'Payload',
     fromAddress: 'hello@payloadcms.com',
   },
diff --git a/demo/server.js b/demo/server.js
index 13ff99eda4..9781723d56 100644
--- a/demo/server.js
+++ b/demo/server.js
@@ -9,9 +9,6 @@ const expressApp = express();
 expressApp.use('/static', express.static(path.resolve(__dirname, 'client/static')));
 
 payload.init({
-  email: {
-    transport: 'mock',
-  },
   secret: 'SECRET_KEY',
   mongoURL: 'mongodb://localhost/payload',
   express: expressApp,
@@ -39,11 +36,6 @@ exports.start = (cb) => {
   const server = expressApp.listen(3000, async () => {
     logger.info(`listening on ${3000}...`);
 
-    const creds = await payload.getMockEmailCredentials();
-    logger.info(`Mock email account username: ${creds.user}`);
-    logger.info(`Mock email account password: ${creds.pass}`);
-    logger.info(`Log in to mock email provider at ${creds.web}`);
-
     if (cb) cb();
   });
 
diff --git a/src/email/build.js b/src/email/build.js
index f4995a4dd8..070f5b54f6 100644
--- a/src/email/build.js
+++ b/src/email/build.js
@@ -5,8 +5,13 @@ const mockHandler = require('./mockHandler');
 async function buildEmail() {
   if (!this.config.email.transport || this.config.email.transport === 'mock') {
     logger.info('E-mail configured with mock configuration');
-    // TODO: Log mock e-mail credentials here as well?
     const mockAccount = await mockHandler(this.config.email);
+    if (this.config.email.transport === 'mock') {
+      const { account: { web, user, pass } } = mockAccount;
+      logger.info(`Log into mock email provider at ${web}`);
+      logger.info(`Mock email account username: ${user}`);
+      logger.info(`Mock email account password: ${pass}`);
+    }
     return mockAccount;
   }
 
diff --git a/src/errors/InvalidConfiguration.js b/src/errors/InvalidConfiguration.js
new file mode 100644
index 0000000000..9943aa9543
--- /dev/null
+++ b/src/errors/InvalidConfiguration.js
@@ -0,0 +1,10 @@
+const httpStatus = require('http-status');
+const APIError = require('./APIError');
+
+class InvalidConfiguration extends APIError {
+  constructor(message, results) {
+    super(message, httpStatus.INTERNAL_SERVER_ERROR, results);
+  }
+}
+
+module.exports = InvalidConfiguration;
diff --git a/src/errors/index.js b/src/errors/index.js
index 0f3239ab6c..6f2f2443a0 100644
--- a/src/errors/index.js
+++ b/src/errors/index.js
@@ -7,6 +7,7 @@ const errorHandler = require('../express/middleware/errorHandler');
 const FileUploadError = require('./FileUploadError');
 const Forbidden = require('./Forbidden');
 const LockedAuth = require('./LockedAuth');
+const InvalidConfiguration = require('./InvalidConfiguration');
 const InvalidFieldRelationship = require('./InvalidFieldRelationship');
 const MissingCollectionLabel = require('./MissingCollectionLabel');
 const MissingFieldInputOptions = require('./MissingFieldInputOptions');
@@ -26,6 +27,7 @@ module.exports = {
   FileUploadError,
   Forbidden,
   LockedAuth,
+  InvalidConfiguration,
   InvalidFieldRelationship,
   MissingCollectionLabel,
   MissingFieldInputOptions,
diff --git a/src/utilities/sanitizeConfig.js b/src/utilities/sanitizeConfig.js
index 314a284520..b6178e9a10 100644
--- a/src/utilities/sanitizeConfig.js
+++ b/src/utilities/sanitizeConfig.js
@@ -35,6 +35,11 @@ const sanitizeConfig = (config) => {
   if (!sanitizedConfig.admin.user) {
     sanitizedConfig.admin.user = 'users';
     sanitizedConfig.collections.push(defaultUser);
+  } else if (!sanitizedConfig.collections
+    .filter((c) => c.auth !== undefined)
+    .map((c) => c.slug)
+    .includes(sanitizedConfig.admin.user)) {
+    throw new InvalidConfiguration(`${sanitizedConfig.admin.user} is not a valid admin user collection`);
   }
 
   sanitizedConfig.email = config.email || {};