Low and intermediate-mass stars evolve through the Post Asymptotic Giant Branch (post-AGB) phase before they reach the Planetary Nebulae stage. After leaving the Main Sequence, they undergo intense episodes of mass loss when in the Giant Branch and, then, they enter the post-AGB stage which is a rather puzzling stellar evolutionary phase . Also, it has a very short duration, of the order of a few thousand years at most, so the number of confirmed post-AGB objects is really small and, thus, our understanding of this elusive evolutionary stage is still very constrained. Post-AGB stars are characterized by infrared excesses and high luminosities. The publication of precise Gaia DR3 parallaxes made it possible to calculate accurate distances and to revise the derivation of luminosities for post-AGB candidates to discard objects outside the expected luminosity range. By identifying post-AGB stars or possible candidates from the literature, then searching for their Gaia DR3 counterparts and using available photometry, interstellar extinction, published spectroscopically derived temperatures or spectral types and parallax-based distances, we fitted their Spectral Energy Distributions (SED) and we estimated their luminosities and circumstellar extinctions. When compared to models, luminosity values allowed us to disclose objects that are likely post-AGB stars from other target types whose observational properties mimic those of post-AGB stars. The position of our selected sample on the Hertzsprung-Russell (HR) diagram allows direct comparison with updated post-AGB evolutionary tracks and an estimation of their masses and evolutionary ages. A summary of the so far obtained outcome will be here presented.