...never thought the aduana was doing anything less than just verifying my passport and airline ticket. thanks for the concern
The last time I left Argentina (through EZE) I remember that, as I approached the check in area, an e
mployee of the airline asked to see my ticket and my passport. I'm sure she was checking the date of my last entry and/or my status with
migraciones.
I had temporary residency at the time so I also produced my DNI. The employee verified that it had not expired and directed me to the appropriate check in line. If my temporary residency had expired I would have been sent to pay the overstay fee and return with the habilitacion de salida stamped by migraciones before being allowed to check in, just like a tourist who had overstayed their 90 day visa.
After checking in I proceeded to the concourse where (for the first time) an official of
migraciones (in one of the glass booths)looked at my DNI and stamped my passport. I was then permitted to proceed to the departure gate.
I'm not sure if the staff at the final security check at he gate are employees of the Aduana (aka customs). In the USA they would be DHS employees. In any case, the Aduana has nothing to do with passport stamps or overstays. It never has and never will.
The reason I continue to make the distinction is that the words Aduana (customs) and migraciones apply to separate entities. The last time I flew out of Argentina I took some original artworks with me and I had to go the the office of the Aduana at EZE to have the packages and papers (which I already received from the Secretary of Culture) cross checked and stamped before I could check in (before the airline would accept the packages as checked baggage).
It was essential to be able to ask where the office of the Aduana was to accomplish this task. The only thing migraciones would have been able to is tell me where to go. Fortunately, I knew which office to ask for and the airline employee told me where to find it.