https://trailhead.salesforce.com/en/content/learn/modules/campaign-management-with-nonprofitsuccess-pack/manage-campaign-responses

To track that a donor responded to the most recent direct mail campaign, the consultant should

configure the Automatic Campaign Member Management feature. This feature in NPSP helps

automatically manage Campaign Memberships based on related opportunities, streamlining the

process of tracking campaign responses.

Steps to Configure:

Enable Automatic Campaign Member Management:

Navigate to NPSP Settings -> Donations -> Campaigns.

Enable Automatic Campaign Member Management.

Link Opportunities to Campaigns:

Ensure that when entering donations, the related Opportunity records are linked to the appropriate

Campaigns.

This linkage will automatically update the Campaign Member records to reflect the donor’s response

to the campaign.

Verify Campaign Membership:

Check the Campaign Member records to ensure that the donors are correctly marked as having

responded to the campaign based on the linked Opportunities.

Reference:

Salesforce Nonprofit Success Pack Documentation

Salesforce Trailhead: Track Campaign Responses with NPSP