Pros
If you're thinking a job as a mail carrier - IMO *especially* as a rural mail carrier - is easy work, like so many seem to do, then think again. You will have to begin as an RCA, & there's not enough room to describe how badly *that* sucks. But, if you eventually become a regular rural mail carrier, it's still the single worst job at the USPS. Not that I think they treat city carriers much better. But years ago, many rural carriers turned down the opportunity to have the NALC as their union, & it's been even further downhill since then. If you want to put the effort into training to move up into a management position, you might do OK. They're taught how to make the peons' lives miserable, but at least they don't get bullied quite as much. Maybe they get bullied most for not making the peons miserable enough, I dunno.
Cons
Postmasters practice favoritism & playing their employees against each other. Must use your own vehicle (even if all you have is a RHD), & the compensation for gas & maintenance keeps decreasing. If you're unfortunate enough to be injured on the job, expect to be ever-more bullied. Not only by your own management, but by the OWCP. They believe that *all* injured employees are really faking it because they're "lazy".