With an eTicket, there is NOTHING we can know FOR SURE. Period. Confirming email - great. What about re-issues? - they occur - sometimes with confirming email - most often without - esp in the case of irrops. What I have found to be most reliable is clicking the "print itin AND RECEIPT" link off your res on AA.COM and if it looks correct, WITH a ticket number, you are probably good to go. (If it just prints itin and not receipt - not so good.) But PROOF POSITIVE - not so much. Only the VCR's have this info - and mere mortal PAX cannot access those. Rarely is there a real problem, but VCR/PNR disconnects are not all that uncommon, so it IS buyer-beware and check, check, check. YMMV