Can spamming from one service affect my deliverability when using another service?
Example: Will emails sent using Salesforce affect deliverability of emails sent using MailChimp?
Take this nighmore scenario as an example. Some guy in our sales department gets kind of crazy with the emails he's sending out. He's hammering a ton of people with a ton of unsolicited email. Eventually the recipients get fed up with this and block him. They may be individuals using a Gmail or Yahoo account. But they may also be small-to-big corporations and their dedicated IT department takes action to stop the emails.
How will this affect my company's deliverability? Let's say we want to send a campaign from email@example.com to people that work for @mycustomer.com. Well Frank in sales abused his access to our EMR (maybe Close.io, maybe Salesforce) and they took action against the email firstname.lastname@example.org. Will I have trouble reaching these people from our MailChimp account?
yes - if frank is a tool, and sends out non can-span emails, or other infractions - your IP WILL get (automatically) added to one (or more of the many) email blacklist ( DNS-based Blackhole List)
Some ISPs opt to use this data to inform their filtering decisions and delivery of the email messages sent over that IP. Note that these lists have no control over delivery or placement of your messages. The blacklist simply serves as a tool to help ISPs make their own decisions.