These are usernames and passwords but your sentiment is correct. Something needs to be fixed there too. First thing is for us to develop good password habits and stop using the same one on several sites.
"redhat.com mailing list memberships reminder"
It's bullshit when people send my password in plaintext to my email account and they ignore my complains when they said "if you have questions send to this owner emaiil." Bullshit. Why do they need to remind me about my password in the first place?
From what I can tell mailman stores thing in plaintext. I personally don't see why anyone can't write 20 lines of code to do a crypt with sha256/sha512 (crypt$5, crypt$6). It's almost idiotic.