Attempting to further navigate through the folder while FETCH was still going on in the background produced the following problems:
Checking IMAP connection to server...
Unable to load message; Wrong type argument: integer-or-marker-p, nil
Retrieving message body... done
Checking IMAP connection to server...
Message body loaded
Checking IMAP connection to server...
Unable to load message; Wrong type argument: integer-or-marker-p, nil
Checking IMAP connection to server...
Unable to load message; Wrong type argument: integer-or-marker-p, nil
Attempting to further navigate through the folder while FETCH was still going on in the background produced the following problems:
Checking IMAP connection to server... or-marker- p, nil or-marker- p, nil or-marker- p, nil
Unable to load message; Wrong type argument: integer-
Retrieving message body... done
Checking IMAP connection to server...
Message body loaded
Checking IMAP connection to server...
Unable to load message; Wrong type argument: integer-
Checking IMAP connection to server...
Unable to load message; Wrong type argument: integer-