It is "the greyest of grey areas" as dicion aptly put it simply because the intent of these signs as well as the kind of party line, word on the street, etc. seems to indicate it is forbidden to carry on the Post Office property, but clearly the law explicitly and directly conflicts the common conception.
If you ask most CHL holders if they think you can carry in the Post Office, almost all of them who confess to know the answer will likely say "no, you cannot". But the law is seemingly both explicit and clear. If the Post Office is a governmental entity, they cannot forbid you from carrying. The very CFR that attempts to forbid carry in the Post Office (among other federal properties) explicitly yields to state law when state law is at conflict with the CFR. So either they are not a governmental entity, and the CFR doesn't apply and they can put up a 30.06 sign, or they are a governmental entity, and the CFR doesn't apply because it is at odds with 30.06(e).
My post from the other thread detailing my opinion on this is here:
http://www.texasshooting.com/TexasCHL_F ... 15#p307346" onclick="window.open(this.href);return false;
FWIW, I don't really think there is any malice on the part of the USPS in TX trying to prohibit us counter to the law. I figure most USPS employees and postmasters do not even know what the TX law is any more than your regular average citizen does, not to mention the majority of CHL holders who have even had a class and taken a test on the law but still miss this. Probably every post office in the country gets these signs sent to them and have a requirement to put them up, and the training given to the postmasters and other USPS employees is not in regard to the specific loopholes of individual state laws, but rather only involves the CFR on a broad basis. Funny thing, I am going to a friend's house who is a senior USPS employee tonight, maybe I will ask exactly what he has been told about this issue. My bet is that they are told that the CFR says thus-and-so, and therefore those are the rules, without any mention of the state law being in conflict and superseding the CFR.
Again I will raise the point that if you think it's not ok to carry inside the Post Office
building, then you are also forbidden from carrying in the
parking lot in most cases, since the CFR refers to "real property" and not "premises" as we are used to in TX law. "Real property" includes the parking lot, and by the way, also likely the neighborhood mailbox cluster as well (if you live in one of these neighborhoods with USPS-managed ganged mailboxes). So you are not really compliant by leaving the gun in your car. Park on the street or next door if you want to be compliant. Of course the MPA also is at conflict with the CFR in this case.