#5.5.0 smtp;530 Authentication required 1

[aarellano]

Hello,

All of the sudden I am getting bounced back emails with the following.

#5.5.0 smtp;530 Authentication required

I have not changed anything on my exchange server, any idea what this might be??

 

[TechyMcSe2k]

Your SPF or reverse DNS is messed up when the email goes outside of your network.


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[aarellano]

is there a way to fix that?

 

[TechyMcSe2k]

contact your ISP for the SPF. Also, who is hosting your Public DNS/namespace? Have them troubleshoot your reverse lookups.

_______________________________________
Great knowledge can be obtained by mastering the Google algorithm.

 

[TechyMcSe2k]

Messages that are sent through Exchange 2003 to an external messaging server are blocked by Sender ID checking

http://support.microsoft.com/kb/915863/en-us

Start Here.

_______________________________________
Great knowledge can be obtained by mastering the Google algorithm.

 

[aarellano]

TechyMcSe2k,
Thank you but I tried that and did not work. I appears that we were listed in a couple of black lists and now that I have taken us out of those black lists everything seems to be back to normal

 

[cmeagan656]

You might want to run anti-malware scans on your network to make sure it isn't infected. Also, check that your Exchange server isn't acting as an open relay. Something caused you to be blacklisted and if you don't find that "something" you're likely to be blacklisted again. The second time around its going to harder to get yourself off the blacklists.

Hope this helps.

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