Since I'm only guessing at what exactly you mean by that, I will say these things.
The USPS has been horribly run for decades (I'm friends with 3 people who have each worked there for 20+ years each). It is long overdue for a HUGE overhaul. Had they been doing the job efficiently, at a reasonable price, we wouldn't have seen all these companies like UPS, FED EX, DHL, etc. come to be.
I hate how Trump is mixing their funding with mail-in votes though. That said, there are a ton of people who vote by mail who are perfectly capable of going to the polls, so I do think it should be a bit more difficult to apply to vote by mail, as it certainly is easier to have fraud that way (for either Party). For example, I am collecting my neighbors' mail this week while they are away. The husband works from home, with flexible hours, the wife is back in school and working PT, and the 20 year old daughter does nothing. They got their mail-in ballots delivered yesterday, although all of them could easily go to the polls. What's keeping me from filling-out their ballots and returning them?
Hope that addresses what you were asking. You may begin criticising now.