About two hours ago, we started seeing a significant uptick in "554 Transaction failed" responses from Microsoft domains. Across all senders. Anyone else seeing this? If I remember correctly, this came up back in Feb. as well.
-- Luke Martinez SendGrid Deliverability Consultant 520.400.5693
_______________________________________________ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop
