Coworker Thank You Card Dilemma

Did you hand deliver the invites? If so, I would discretely hand deliver the thank you notes. Maybe get there early in the morning and place them on their desk/work area before anyone gets there. Maybe HR can send the thank yous for you if they dont want to release the addresses.

I agree with this. Being discrete is your best option here because you're not wanting to hurt others' feelings. I wouldn't do an email because it just seems a bit impersonal to me, but I think it's a know your crowd kind of thing!

I would discretely hand deliver, or email and ask for their address so you can mail.

I have left thank you notes on co-workers desks either after they have left for the day or before they arrived in the morning because I did not want others to see me physically handing them out. If you did not want to do that, I don't see anything wrong with emailing them individually to ask for their addresses.

I would just hand deliver them, leaving them on desks when nobody is around. I understand that you don't want to "call anyone out" but you do want to make sure you give a thank you card to everyone who gave you a gift. Just get there a little early, before anyone else, and leave them for each person on their desk.