Email Copilot Blog Major ESP Not Adjusting for "450 Too Many Connections" Deferrals

A major ESP was not honoring a receiving email server's requests to "back off". This resulted in 250 deferrals for each email being delivered, and 1M deferrals per week to this one specific domain. Email Copilot identified the problem in about 3 hours and the ESP resolved it that day. Their customer was ecstatic.