Apparently Bravo producer Andy Cohen forgot to stick a stamp on his invite to RHONJ's Danielle Staub because she never got it!

After much back-and-forth -- Danielle was already in LA but without an invite, RHOBH star Kyle Richards was hosting the baby shower at Beverly Hills hotspot The Palms and maybe didn't want Danielle there???, but Andy personally called Staub to invite her once he realized there'd been a mishap with the invite and now ... Danielle says it's all good.

When Staub first realized she was in LA without an invite, her rep told Page Six: "Danielle came to Los Angeles to film a video promotion for the movie ‘Greta.’ While she was here, there was a misunderstanding regarding the baby shower. There’s no issue or drama, Danielle is fine and life goes on.” her rep, Steve Honig said.