diff --git a/Lib/imaplib.py b/Lib/imaplib.py
index 4586fb3..10ff340 100644
--- a/Lib/imaplib.py
+++ b/Lib/imaplib.py
@@ -1002,6 +1002,11 @@
                 del self.tagged_commands[tag]
                 return result
 
+            # If we've seen a BYE at this point, the socket will be
+            # closed, so report the BYE now.
+
+            self._check_bye()
+
             # Some have reported "unexpected response" exceptions.
             # Note that ignoring them here causes loops.
             # Instead, send me details of the unexpected response and
diff --git a/Misc/NEWS b/Misc/NEWS
index 9520fa4..9479ded 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -42,6 +42,10 @@
 Library
 -------
 
+- Issue #20013: Some imap servers disconnect if the current mailbox is
+  deleted, and imaplib did not handle that case gracefully.  Now it
+  handles the 'bye' correctly.
+
 - Issue #20426: When passing the re.DEBUG flag, re.compile() displays the
   debug output every time it is called, regardless of the compilation cache.