diff --git a/src/com/fsck/k9/mail/transport/SmtpTransport.java b/src/com/fsck/k9/mail/transport/SmtpTransport.java
index 45f218191..7906ca5db 100644
--- a/src/com/fsck/k9/mail/transport/SmtpTransport.java
+++ b/src/com/fsck/k9/mail/transport/SmtpTransport.java
@@ -171,7 +171,7 @@ public class SmtpTransport extends Transport {
             executeSimpleCommand(null);
 
             InetAddress localAddress = mSocket.getLocalAddress();
-            String localHost = localAddress.getHostName();
+            String localHost = localAddress.getCanonicalHostName();
             String ipAddr = localAddress.getHostAddress();
 
             if (localHost.equals("") || localHost.equals(ipAddr) || localHost.contains("_")) {