diff --git a/spring-context-support/src/main/java/org/springframework/mail/javamail/JavaMailSenderImpl.java b/spring-context-support/src/main/java/org/springframework/mail/javamail/JavaMailSenderImpl.java
index 51cd48113cb6..18f09acd2e1d 100644
--- a/spring-context-support/src/main/java/org/springframework/mail/javamail/JavaMailSenderImpl.java
+++ b/spring-context-support/src/main/java/org/springframework/mail/javamail/JavaMailSenderImpl.java
@@ -459,6 +459,7 @@ protected void doSend(MimeMessage[] mimeMessages, @Nullable Object[] originalMes
 						// Preserve explicitly specified message id...
 						mimeMessage.setHeader(HEADER_MESSAGE_ID, messageId);
 					}
+					Assert.notNull(mimeMessage.getAllRecipients(), "At least one recipient is required");
 					transport.sendMessage(mimeMessage, mimeMessage.getAllRecipients());
 				}
 				catch (Exception ex) {