Wow! Thanks.

Can this be made a sticky?

I thought I would update the airport mailbox list in alphabetical order and with some new airports and new airport information
ABQ-Curbside level 2
ATL-Presecurity south terminal across from baggage claim one
AUS-Ticketing level between AA and WN ticket counters
AZO-In the entry of the first entrance of the terminal

I thought I would update the airport mailbox list in alphabetical order and with some new airports and new airport information
ABQ-Curbside level 2
ATL-Presecurity south terminal across from baggage claim one
AUS-Ticketing level between AA and WN ticket counters
AZO-In the entry of the first entrance of the terminal
BDL-Second floor near US/UA curbside check in
BNA-Baggage claim near information desk
BOS-Baggage claim Terminal B/AA terminal
BTR-Next to DL ticket counter
BUR-Terminal A curbside
BWI-Front of Concourse C/Behind US ticket counter/prior to concourse E
CAE-Upper level near information desk
CAK-Curbside
CID-Lobby next to ticket counters/restaurant gift shop
CLE-Prior to security checkpoint next to AA ticket counter
CLT-Concourse D/E next to atm
CRW-Lobby across from US ticket counter
CVG-Terminal 2 prior to security checkpoint
DAB-Curbside baggage claim next to taxi stand
DCA-Concourse level near atm
DEN-Post office main terminal prior to security checkpoint
DFW-Gate A20/Gate B14/Gate C12/Gate D23/Gate E11
DTW-Macnamara terminal middle of concourse A
ELP-Lobby between ticket counter and baggage claim
EUG-Curbside
FNT-Outside main entrance doors
GNV-In front of terminal
GPT-Outside of terminal left side of building
GSO-Upper level outside doors beside PGA shop
GSP-First floor near escalator
HOU-Central lobby prior to security
HRL-Outside to the right of main entry doors
HSV-First floor across from AA ticket counter
IAD-Ground transportation level near bag claim 13 behind gift shop and ground transportation desk
IAH-Terminal A ticketing lobby
ICT-Across the street from center terminal doors
IND-Next to information desk second floor prior to security checkpoint
JAX-Second floor near escalator
LAS-Post office-terminal one Level two prior to security
LEX-Curbside
LIT-Curbside in front of ticket counters
MCO-Level three Terminal A across from bank
MDT-Second floor
MEM-Baggage claim Terminal A
MFE-Located by arrivals door
MLB-On the wall next to museum near ticket counters
MIA-Across from AA ticket counters/Across from secuirty Checkpoint E/across from security checkpoint F/across from security checkpoint G /across from security checkpoint H- all are pre security
MKE-Upper level between Concourse C and D
MOB-Curbside ticket counter/Level two prior to security checkpoint
MSP-Gate C2/Gate C13/Gate F4/past security checkpoint 4
MSY-Ticketing lobby
OAK-Located curbside near crosswalk terminal one
OKC-Baggage claim four
ORD-Between concourse K and L post security
ORF-Second level main terminal near walkway to baggage claim
PBI-First floor next to escalator east end of terminal
PDX-Prior to security checkpoints
PHF-Main atrium
PHL-Near Gate A1/gate A17/Terminal C/D walkway /Gate F10
PHX-Curbside Terminal2/3/4
PIT-Post Office-concourse D/Mailbox near information desk skymall post security
PNS-Outside across from airline ticketing area
PSP-Outside main terminal near center door behind wall
RDU-Curbside terminal one
RIC-Curbside near parking garage ground level
RNO-Curbside baggage claim
ROA-Baggage claim
RSW-Business center prior to concourse B
SAN-Curbside commuter terminal/terminal one/two
SAV-First floor near information desk
SEA-Baggage claim door 16/between US/WN ticket counter/near AA ticket counter/Across from Gate A3/Concourse B entrance/Concourse C entrance/Concourse D across from Hudson news
SFO-Curbside terminal one/three
SJC-Terminal A -baggage claim two/Terminal B-north side of ticketing area
SLC-Top of escalator concourse A/just before concourse D connector post security
SRQ-First floor near ticket counter prior to escalator
STL- Main terminal-Baggage claim
TLH-Located adjacent to two center doors entering front of terminal
TPA-On side of elevators/baggage claim/ticketing/transfer levels
TRI-Information desk prior to security
TUS-Wall prior to security checkpoint
TYS-Second floor hallway prior to security checkpoint
XNA-Baggage claim next to escalator

I can confirm the airside mailboxes at MSP, DTW, and DCA, as well as the airside post office at PIT, good for buying commemorative stamps when you have time to kill, and the land side post office at ATL. There is also a land side mailbox at MSP on the arrivals level and a full post office that keeps long hours, later than the downtown Minneapolis location, on airport property, although I do not think you can walk there from the terminals as the roadway exiting the airport terminal area has no sidewalk.

DUB has one

Air-side mailbox at IAH?
 

Is there an airside mailbox at Houston IAH?

The airport website mentions mailboxes at the terminals A, B, and D ticketing areas, but nothing inside security.