Let me check that I understand this correctly... Person A is offline; Person B sends A a message with reply-all disabled; Person A comes back online but the received message does not have reply-all disabled. Is that right?
Hmmm: that shouldn't happen, and doesn't seem to be happening on my machine - not that that's a lot of help or comfort to you. What version of Outlook are you using, in case that makes a difference - I've only tested Outlook 2013 (32-bit with
latest Windows Updates) so far.