Certain email addresses are honeypots. These are email addresses that are used to detect spammers. There are thousands of spam bots searching the web for anything that looks like an email address to add to their spam database. They collect millions of addresses and start sending them spam. They also sell those addresses to other spammers which means those email addresses get an abundance of unwanted emails.
The purpose of a honeypot address is to detect spammers. These email addresses are added to websites, often hidden from actual human users, to trap spammers. Once an email is received at a honeypot address, the sender is flagged as a spammer and blacklisted.
Whether you acquired a honeypot email from a trusted partner email list, a competitor entering the email address on your website, or by an accidental typo, the result is the same. You will be labeled a spammer if you send an email to a honeypot email address.