diff --git a/src/mail.js b/src/mail.js
index 4f0450c4e..2fc4ceff6 100644
--- a/src/mail.js
+++ b/src/mail.js
@@ -241,12 +241,10 @@ async function checkSmtpRelay(relay) {
     if (relay.provider === 'noop') return { status: 'skipped', message: 'Outbound disabled' };
     if (relay.provider === 'cloudron-smtp') {
         const results = await Promise.allSettled([ checkOutboundPort25(4), checkOutboundPort25(6) ]);
-        if (results[0].status === 'fulfilled' && results[1].status === 'fulfilled') return { status: 'passed', message: 'Port 25 (outbound) is unblocked' };
-        const messages = [];
-        if (results[0].status === 'rejected') messages.push(results[0].reason.message);
-        if (results[1].status === 'rejected') messages.push(results[1].reason.message);
-        messages.push('Check if port 25 (outbound) is blocked.');
-        return { status: 'failed', message: messages.join('. ') };
+        if (results[0].status === 'fulfilled' && results[1].status === 'fulfilled') return { status: 'passed', message: 'Port 25 outbound is unblocked' };
+        if (results[0].status === 'fulfilled') return { status: 'passed', message: 'IPv4 port 25 outbound is unblocked. IPv6 port 25 outbound is blocked and delivery to IPv6 only servers will fail,' }; // ipv6 only servers are not really common
+        if (results[1].status === 'fulfilled') return { status: 'failed', message: `IPv4 port 25 outbound is blocked: ${results[0].reason.message}.` }; // only IPv6 worked
+        return { status: 'failed', message: `Port 25 outbound is blocked. ${results[0].reason.message}` }; // both failed
     }
 
     const options = {