yeah the gateway thing is totally normal, closest isnt always best especially on HF. propagation is everything and a gateway thats 300 miles away might just be hitting a better path to you than the one 80 miles out. Winlink Express does have that auto-connect feature where it'll try a few in the list if the first one fails, worth enabling that if you havent already. i usually just let it scan through 4 or 5 and it finds something workable most of the time. on the email reply issue — your winlink address should be
[email protected] and replies to that from regular email do work but theres sometimes a delay and occasionally they get filtered depending on the sending mail server. did the bounce message give you any detail? if it was a hard bounce thats different than a soft one. also double check theres no space or weird character in the address because ive seen that trip people up more than once. the system itself isnt that fragile once its set up right.