I don't know.
I could tell you about the linux version, but I think the Mac version is
different.
And one thing, the version of Linux that I've used since 2001, pine used
to keep the password, but now I have to enter the password every time. A
change in the configuration, or maybe a change in the default because of
the move to Alpine, so it's no longer compiled to keep track of the
password. That may be your issue, I don't know.
This has certainly been discussed in this newsgroup in the past.
Michael