diff --git a/endpoints/slack-invite.js b/endpoints/slack-invite.js
index 1487d9c..fefcc55 100644
--- a/endpoints/slack-invite.js
+++ b/endpoints/slack-invite.js
@@ -1,4 +1,6 @@
+const { client } = require('../app')
 const { inviteUser } = require('../util/invite-user')
+const { transcript } = require('../util/transcript')
 
 module.exports = async function slackInvite(req, res) {
   // this endpoint is hit by the form on hackclub.com/slack
@@ -13,13 +15,79 @@ module.exports = async function slackInvite(req, res) {
     const email = req?.body?.email
     const result = { email }
     if (email) {
-      const { ok, error } = await inviteUser(req.body)
-      result.ok = ok
-      result.error = error
+      const res = await inviteUser(req.body)
+      result.ok = res.ok
+      result.error = res.error
+      let invites = res?.invites
+      if (invites) {
+        result.error = invites[0]?.error
+        result.ok = result.ok
+      }
+      if (result.error === 'already_in_team') {
+        // User is already in Slack - send them an email via Loops telling them how to login
+        let email = res?.invites[0]?.email
+        let userInfo = await client.users.lookupByEmail({ email })
+        let isMcg = userInfo?.user?.is_restricted
+        let isScg = userInfo?.user?.is_ultra_restricted
+        let dataVariables
+        let transactionalId
+        if (isMcg) {
+          // Check if they're in cave channel, invite if not
+          await client.conversations
+            .invite({
+              channel: transcript('channels.cave'),
+              users: userInfo.user.id,
+              token: process.env.SLACK_USER_TOKEN,
+            })
+            .catch((err) => {
+              if (err.data.error === 'already_in_channel') {
+                // User is already in channel, do nothing
+              } else {
+                console.log(err)
+              }
+            })
+          let caveChannelData = await client.conversations.info({
+            channel: transcript('channels.cave'),
+          })
+          let caveChannelName = caveChannelData.channel.name
+
+          dataVariables = {
+            email,
+            caveChannelName: caveChannelName,
+            caveChannelUrl: `https://hackclub.slack.com/archives/${transcript('channels.cave')}`,
+          }
+          transactionalId = process.env.LOOPS_MCG_TRANSACTIONAL_ID
+        } else if (isScg) {
+          // We shouldn't really have any of these and if we do, we likely don't want to promote them
+          return res.status(500).json({
+            ok: false,
+            error: 'User is already in Slack but is an SCG',
+          })
+        } else {
+          // Full user, don't invite to chanel - just set the full user template
+          dataVariables = {
+            email,
+          }
+          transactionalId = process.env.LOOPS_FULL_USER_TRANSACTIONAL_ID
+        }
+
+        const lres = await fetch('https://app.loops.so/api/v1/transactional', {
+          method: 'POST',
+          headers: {
+            'Content-Type': 'application/json',
+            Authorization: `Bearer ${process.env.LOOPS_API_KEY}`,
+          },
+          body: JSON.stringify({
+            email,
+            transactionalId,
+            dataVariables,
+          }),
+        })
+      }
     }
-    res.json(result)
+    return res.json(result)
   } catch (e) {
     console.log(e)
-    res.status(500).json({ ok: false, error: 'a fatal error occurred' })
+    return res.status(500).json({ ok: false, error: 'a fatal error occurred' })
   }
 }
diff --git a/util/invite-user.js b/util/invite-user.js
index 08d35b8..0348be7 100644
--- a/util/invite-user.js
+++ b/util/invite-user.js
@@ -20,7 +20,6 @@ async function inviteGuestToSlack({ email, channels, _customMessage }) {
   headers.append('Cookie', cookieValue)
   headers.append('Content-Type', 'application/json')
   headers.append('Authorization', `Bearer ${process.env.SLACK_BROWSER_TOKEN}`)
-
   const data = JSON.stringify({
     token: process.env.SLACK_BROWSER_TOKEN,
     invites: [