[quote user="Euler GERMAN"]
Queued messages are represented as a pair of files while they still editable. The content (body) part is a PNX file and it MUST have a counter part, either a PMX (headers, etc) or a PMO (ditto, but for saved, auto-saved or stationary). A queued message should appear like 12345678.PNX and 12345678.PMX (or PMO). After processing to its final form it will appear as 12345678.PMW only.
If you have broken file pairs you most likely will have a ghost queued message. Corrupted files also may be a cause, but I'd look after PNXs without PMXs (or PMOs), or vice-versa. Delete them if found.
Deleted 2 related PMX & PMW files in Mail directory, FIXED THE PROBLEM.