diff --git a/migrations/users/bulk-email.js b/migrations/users/bulk-email.js
index 88f67e095f..611a5ad463 100644
--- a/migrations/users/bulk-email.js
+++ b/migrations/users/bulk-email.js
@@ -16,7 +16,7 @@ async function updateUser (user) {
 
   if (count % progressCount === 0) console.warn(`${count} ${user._id}`);
 
-  sendTxn(
+  await sendTxn(
     user,
     EMAIL_SLUG,
     [{ name: 'BASE_URL', content: BASE_URL }], // Add variables from template
diff --git a/website/server/libs/email.js b/website/server/libs/email.js
index 634d60ad9d..4620f980fe 100644
--- a/website/server/libs/email.js
+++ b/website/server/libs/email.js
@@ -66,7 +66,7 @@ export function getGroupUrl (group) {
 }
 
 // Send a transactional email using Mandrill through the external email server
-export function sendTxn (mailingInfoArray, emailType, variables, personalVariables) {
+export async function sendTxn (mailingInfoArray, emailType, variables, personalVariables) {
   mailingInfoArray = Array.isArray(mailingInfoArray) ? mailingInfoArray : [mailingInfoArray]; // eslint-disable-line no-param-reassign, max-len
 
   variables = [ // eslint-disable-line no-param-reassign, max-len
@@ -130,7 +130,7 @@ export function sendTxn (mailingInfoArray, emailType, variables, personalVariabl
   }
 
   if (IS_PROD && mailingInfoArray.length > 0) {
-    got.post(`${EMAIL_SERVER.url}/job`, {
+    return got.post(`${EMAIL_SERVER.url}/job`, {
       auth: `${EMAIL_SERVER.auth.user}:${EMAIL_SERVER.auth.password}`,
       json: true,
       body: {
@@ -149,4 +149,6 @@ export function sendTxn (mailingInfoArray, emailType, variables, personalVariabl
       },
     }).catch(err => logger.error(err));
   }
+
+  return null;
 }