POP3: trash folder remains empty
Hi,
When i delete a mail, the trash folder remains empty
[log.txt](https://github.com/k9mail/k-9/files/4505545/log.txt)


### Expected behavior
Deleted mail should be found in the trash folder

### Actual behavior
No mail is found in the trash folder

### Steps to reproduce
1. delete a mail
2. go to the trash folder
3. see if the deleted mail is in the folder

### Environment
K-9 Mail version: 5.708

Android version: 10

Account type (IMAP, POP3, WebDAV/Exchange): pop3

diff --git a/app/core/src/main/java/com/fsck/k9/controller/MessagingController.java b/app/core/src/main/java/com/fsck/k9/controller/MessagingController.java
index 337b8c54a..785bd60e5 100644
--- a/app/core/src/main/java/com/fsck/k9/controller/MessagingController.java
+++ b/app/core/src/main/java/com/fsck/k9/controller/MessagingController.java
@@ -2034,7 +2034,7 @@ public class MessagingController {
             localFolder = localStore.getFolder(folder);
             Map<String, String> uidMap = null;
             if (folder.equals(account.getTrashFolder()) || !account.hasTrashFolder() ||
-                    !backend.isDeleteMoveToTrash()) {
+                    (backend.getSupportsTrashFolder() && !backend.isDeleteMoveToTrash())) {
                 Timber.d("Not moving deleted messages to local Trash folder. Removing local copies.");
 
                 if (!localOnlyMessages.isEmpty()) {
['app/core/src/main/java/com/fsck/k9/controller/MessagingController.java']