relaycheckhq.com

check.relaycheckhq.com hosts infrastructure used to verify whether an email address can accept mail (SMTP RCPT probes). It does not send marketing or transactional product email.

• Probes never send message bodies (DATA)
• Rate-limited per destination provider
• Separate from NudeTool sending domains

Abuse / contact: abuse@relaycheckhq.com