diff --git a/ImapClient.cs b/ImapClient.cs
index f92baf4..d8f63ac 100644
--- a/ImapClient.cs
+++ b/ImapClient.cs
@@ -1628,7 +1628,7 @@ public void CopyMessages(IEnumerable<uint> uids, string destination, string mail
 				SelectMailbox(mailbox);
 				string tag = GetTag();
 				string response = SendCommandGetResponse(tag + "UID COPY " + set + " " +
-					destination.QuoteString());
+					Util.UTF7Encode(destination).QuoteString());
 				while (response.StartsWith("*"))
 					response = GetResponse();
 				ResumeIdling();
@@ -2290,4 +2290,4 @@ void AssertValid(bool requireAuth = true) {
 	/// <returns>true to include the body part in the returned MailMessage object, or false to skip
 	/// it.</returns>
 	public delegate bool ExaminePartDelegate(Bodypart part);
-}
\ No newline at end of file
+}