Do you see anything like this
Purging IMAP items marked for deletion
When you mark an item on an IMAP e-mail server for deletion, the item is displayed in strikethrough text in the header list. However, the item isn't removed from the IMAP mail server until a purge command is used.
Tip: You can change the view of an IMAP folder so that items marked for deletion do not appear. On the
View menu, point to
Current View, and then click
Hide Messages Marked for Deletion. If you are using the Reading Pane, you must turn it back on after using this command. On the
View menu, point to
Reading Pane, and then click
Right or
Bottom.
If you don't purge deleted items periodically, you might reach and exceed the allotted disk space on your e-mail server. If you exceed your allotted disk space, you might not receive any new messages.
Note: You must be working online with the mail server for these features to work.
Manually purge deleted items
To permanently delete the items marked for deletion, do the following:
- Click a folder in your IMAP e-mail account.
- On the Edit menu, point to Purge Deleted Messages.
- Do one of the following:
- Click Purge Marked Items in "folder".
Only items marked for deletion in the folder that you're in are purged from the IMAP mail server.
- Click Purge Marked Items in "e-mail account".
All items marked for deletion in any folder for this IMAP e-mail account are purged from the IMAP mail server.
- Click Purge Marked Items in All Accounts.
All items marked for deletion in any folder for any IMAP e-mail account are purged from the IMAP mail server.
Tip: Add the
Purge command to a toolbar. On the
Tools menu, click
Customize. On the
Commands tab, under
Categories, click
Edit. Under
Commands, drag the
Purge command to a toolbar.
Automatically purge the deleted items
You can configure Microsoft Outlook so that when you switch between folders, any items you have marked for deletion are purged from the IMAP mail server.
- Click a folder in your IMAP e-mail account.
- On the Edit menu, point to Purge Deleted Messages.
- Click Purge Options.
The Internet E-mail Settings dialog box opens.
- On the General tab, under Purge Options, select the Purge items when switching folders while online check box.
SOURCE:
https://support.office.com/en-us/ar...80420&ui=en-US&rs=en-US&ad=US#ID0EAABAAA=2007
You might want to click "Purge Options"