We present preliminary results on an XMM-Newton observation dedicated to Post-T-Tauri (PTT) stars. We observed the visual binary 2RE J0241-53 of the Horologium association of nearby PTT stars. The XMM observations have been complemented with ground-based optical spectroscopy and photometry. Several flares have been observed. The X-ray spectrum of the brightest star during quiescence indicates a rather cool corona (with no emission at temperatures ⩾10 MK) more similar to that of the Classical T-Tauri star TW Hya (observed with Chandra and XMM-Newton) and at variance with that of another PTT Star (PZ Tel) observed with Chandra. Approximate analysis shows large Ne/Fe, N/Fe, C/Fe abundances (compared to solar photospheric values).