Undeliverable emails
Having some emails bounce back with this message:
550-5.7.1 [173.203.187.105] Messages missing a valid messageId header
are not 550 5.7.1 accepted.
How can we fix this problem Thanks
Having some emails bounce back with this message:
550-5.7.1 [173.203.187.105] Messages missing a valid messageId header
are not 550 5.7.1 accepted.
How can we fix this problem
Thanks
All Replies (1)
This is an issue between the two mail servers. This URL may give some insight: https://www.hostwinds.com/tutorials/550-5-7-1-error-when-sending-email