I searched my email addresses in https://haveibeenpwned.com/.
One of my e-mail addresses results as having been pwned, and is present in a data breach, in particular the Apollo data breach:
Apollo: In July 2018, the sales engagement startup Apollo left a database containing billions of data points publicly exposed without a password. The data was discovered by security researcher Vinny Troia who subsequently sent a subset of the data containing 126 million unique email addresses to Have I Been Pwned. The data left exposed by Apollo was used in their "revenue acceleration platform" and included personal information such as names and email addresses as well as professional information including places of employment, the roles people hold and where they're located. Apollo stressed that the exposed data did not include sensitive information such as passwords, social security numbers or financial data. The Apollo website has a contact form for those looking to get in touch with the organisation.
I have never subscribed to Apollo or given my address to Apollo.
How do they have my e-mail address in the first place?