For distinguishing between "legitimate advertisers" and "shady, definitely con artists", sure.
For distinguishing between e-mail I actually care about and e-mail I'd like to insta-delete and not see any more, not so sure. On my work account, I get email from supervisors, coworkers, colleagues, external business partners, external salesmen. For the most part, only the generic sales pitches from external vendors have "unsubscribe" links. And on my personal account, I get email from family, friends, open-source collaborators, volunteer-work collaborators, religious associates, former colleagues, businesses I'm dealing with, lawyers I'm dealing with, and recruiters. There as well, the truly personal messages are unlikely to have "unsuscribe" links, while the generic advertisements for things I'm not even interested in often do have a purported "unsubscribe" link.
Both my church and a non-sectarian youth development organization I'm involved with seem to have gotten caught in the spam-fighting crossfire this year. Each had a system that allowed members of the organization to send e-mail to other members; in the church, for local leaders to reach their own congregation; in the youth organization, for "unit leaders" to put items on a calendar, which would send out reminders at a set time before the event. The youth organization's systems were actually put on a well-known spam list, and I've also heard reports from people who just didn't get messages I sent through the church's system. On the other hand, mail from the "unofficial" channel of my personal address to the same people seems to have still gone through during the same timeframe.