Microsoft
Software
Hardware
Network
Question : SMTP Server Returned: 451 4.1.8
A client's email is bouncing back with the following message:
Message is waiting at home for delivery to smtpi.xxx.net.
Message delivery has been delayed to the following recipients:
Recipient: [SMTP:
[email protected]
]
Reason: Remote SMTP Server Returned: 451 4.1.8
Possibly forged hostname for 67.222.136.xxx
I did a blacklist check which returned entries in FIVETENFREE, FIVETENIGNORE, FIVETENKLEZ, FIVETENMULTI, FIVETENOPTIN, FIVETENOTHER, FIVETENSINGLE, FIVETENSRC, FIVETENTCPA, FIVETENWEBFORM, and OSPAM.
First question is, I am confident my client has not sent unsolicited emails, but they recently upgraded to a new server with a different IP range, so perhaps this range was already blacklisted?
Is "Remote SMTP Server Returned: 451 4.1.8" indicative of blacklisting, or something else entirely?
Thanks!
Rick
Answer : SMTP Server Returned: 451 4.1.8
I ordered a new IP range and the problem disappeared. Case closed.
Random Solutions
Cisco PIX client VPN question
Need explanation on static IP's, port forwarding to multiple machines, and how to set up my network
IIS - Max URL Length?
Reverse DNS Failed ...
need help setting up a 3845 with a t3 card to be used as a ptp between offices!!!
I can see other computer, but others cannot see my computer
How To Setup Root Hints DNS
Looking for a good Dual SSID Router & Access Point
Using 2 Windows DHCP Servers on one AD Domain
Suggestion for final year project's topic