I just give them the record locator which is issued to you via email. Also, to my surprise after the last e-ticket out of POP , the AA counter agent asked me to produce the credit card that I used online. Not sure if that is a policy they've continued with at POP.
I've never been asked for my e-ticket; I just give my passport, and AA brings up my record, no problem. You can also now print your boarding pass for international flights within 24 hours of departure.
Does POP have the new self-serve check-in machines or just Santo Domingo?
...was asked by the ... agent for the credit card I used on the online transaction. The agent saw the CC gave it back to me and all was good.