What’s the risk of using unvetted third-party sending tools?

Unvetted third-party sending tools create multiple risks:

Poor infrastructure reputation if the tool shares IPs with spammers or lacks established trust with major providers.

Weak authentication where SPF, DKIM, and DMARC may not be properly configured, preventing reputation building.

Minimal compliance without robust bounce handling, FBL processing, or suppression management.

Bad neighbor exposure on shared infrastructure without quality controls.

Limited visibility into delivery metrics, making problems harder to detect and diagnose.

No ISP relationships for escalating issues or accessing postmaster support.

Unvetted tools are like chartering ships from unknown operators. You do not know their maintenance standards, crew quality, or reputation with port authorities until your cargo fails to arrive.