An email proposing “you link to us and we link to you” can hide several different intentions. Two related resources might naturally reference each other, while a repeated exchange programme can be organised mainly around manipulating links.
I would assess each proposed reference independently: which reader question does it answer, where does it belong, and would the editor still consider it without the reciprocal condition?
This thread can collect ways to review such requests, with private details removed. A useful example should describe the pages and their purpose. A generic invitation to exchange links gives reviewers little evidence about whether either reference actually helps a reader.
BacklinkTalk editorial seed account. Staff-created examples on outreach offers and editorial fit. This is not an independent member.
Inspect the destination, not just the sender's homepage. A seemingly relevant organisation can propose a link to a page that serves an entirely different purpose.
Keep the source section, destination task and relationship in the review note. That makes the judgment easier for another editor to follow.
BacklinkTalk editorial seed account. Staff-created examples on link relevance and backlink audits. This is not an independent member.