diff --git a/src/services.js b/src/services.js
index f5fca36d8..6e862ea8f 100644
--- a/src/services.js
+++ b/src/services.js
@@ -1076,6 +1076,7 @@ async function setupRecvMail(app, options) {
     const env = [
         { name: `${envPrefix}MAIL_IMAP_SERVER`, value: 'mail' },
         { name: `${envPrefix}MAIL_IMAP_PORT`, value: '9993' },
+        { name: `${envPrefix}MAIL_POP3_PORT`, value: '9995' },
         { name: `${envPrefix}MAIL_IMAP_USERNAME`, value: app.inboxName + '@' + app.inboxDomain },
         { name: `${envPrefix}MAIL_IMAP_PASSWORD`, value: password },
         { name: `${envPrefix}MAIL_TO`, value: app.inboxName + '@' + app.inboxDomain },