Just a quick hint if you want to contain legal spam under GDPR.
Recital (14) “The protection afforded by this Regulation should apply to natural persons, whatever their nationality or place of residence, in relation to the processing of their personal data. This Regulation does not cover the processing of personal data which concerns legal persons and in particular undertakings established as legal persons, including the name and the form of the legal person and the contact details of the legal person. ”
Recital (26) “The principles of data protection should apply to any information concerning an identified or identifiable natural person. ”
In short, GDPR only applies to natural persons (people breathing), not to legal person (like, the thing with a VAT number or company registration nr).
So: Companies/legal persons can be legally contacted or spammed.
Conclusion: use a general mail address (like info@ or company@) in all non-personal company registrations and contact details, white pages, yellow pages, VAT or government paperwork…
Make sure your official company registration DOES NOT refer to a personal address.
And as owner or delegate, keep your mail address for your personal professional communication, eg signature with personally identifiable contact details (mail, phone, mobile, skype, IM, …).
Because then your personal mail account is related to an identified and identifiable natural person, and covered by GDPR, protected from direct marketing violations. Should be.