Instead, I just blacklist the sender's IP address. It's even nicer when the sender (e.g. LinkedIn) publishes TXT RRs for SPF in their DNS zone as it allows me to easily blacklist all of them.
Whether you consider this good or bad may vary: it means MSPs have a valid claim that senders exercise Good Citizen practices on all mailings, not just those circulating via the MSP.
Then there are the major players. Yahoo's been a freaking PITA for years on outbound spam (both spam and joe-job bounces), with no effective reporting mechanism. Gmail's been largely better IME, other providers vary.
So in this case, mailchimp is getting marked as spam, even though they are an honest player.
If the unsub requires me to log in first, I mark it spam instead. If the link looks fishy and/or I can't readily discern it's of any quality it's spam. If I have no clue why I could've gotten the message it gets flagged for sure.
Luckily for me I get very few emails per month that I don't know why I would've gotten them, so it isn't a painful exercise to give them a chance to not get flagged.
I use Unroll.me[0] to manage the messages I do want to get, but want to check on my own time and I don't want them sitting in my inbox. I'm sure there are other types of services, but I'm generally happy with what they do. They also can manage a lot of the opt-out features as well, not sure if it 'protects' me any more than doing it myself though.
#6: https://www.ftc.gov/tips-advice/business-center/guidance/can...
1. If I start receiving spam I know who leaked my address
2. If I can't switch off the spam hose, I just delete the alias, which severs any way this website can contact or bug me.
It should be generalised. All it requires is a sort of index to remember who was given what alias.