Human resources, unions, occupational health and legal correspondence should be excluded before anything is read. Why filtering afterwards is not enough.
Every mailbox contains correspondence that has nothing to do with business relationships and a great deal to do with privacy. Messages with human resources about a grievance. Threads with a union representative. Notes with occupational health. Conversations with lawyers. Under European data protection law, several of these involve special categories of personal data that carry the strictest protections.
Many tools read everything and then filter out what looks sensitive. That means the sensitive mail has already been processed, even if nothing from it is kept. The safer design excludes those categories before anything is read at all.
For the mail that remains, a contact discovery tool needs very little: who sent it, who received it, and the meeting invitations and saved contacts in the account. Message bodies and attachments are not needed to find a business contact. Reading a signature block for a job title should be a separate permission, off unless the customer turns it on, and processed in memory only.
RelationLens reads message headers, calendar invitations and saved contacts. Message bodies, attachments and files are never stored. Sensitive categories are excluded before anything is read, and a configuration with no message body access at all is fully supported. Your administrator decides what may be read and what is excluded, on one screen with no code.