diff --git a/application/imap-service.js b/application/imap-service.js
index 190ae2c..1123ec8 100644
--- a/application/imap-service.js
+++ b/application/imap-service.js
@@ -254,6 +254,8 @@ class ImapService extends EventEmitter {
 			.map(addressObj => addressObj.address)
 
 		const from = headerPart.from.flatMap(from => addressparser(from))
+
+		// Specify default subject, in case none exists.
 		let subject = "No Subject"
 		try {
 			subject = headerPart.subject[0]
diff --git a/infrastructure/web/routes/inbox.js b/infrastructure/web/routes/inbox.js
index 04cf3f3..f99f535 100644
--- a/infrastructure/web/routes/inbox.js
+++ b/infrastructure/web/routes/inbox.js
@@ -33,6 +33,12 @@ router.get(
 				req.params.uid
 			)
 			if (mail) {
+
+				// Set a default subject if none is present
+				if (!mail.subject) {
+					mail.subject = 'No Subject'
+				}
+
 				// Emails are immutable, cache if found
 				res.set('Cache-Control', 'private, max-age=600')
 				res.render('mail', {