exchange 16 open relay
How do I close my exchange server from being an open relay. I am running exchange 16, and earlier today, i thought it was configured to NOT be an open relay.
I since made a lot of changes today and when I just checked, looks like I'm an open relay. I'm sure it's some permissions issue in one of the connectors, I just
don't remember which one.
I since made a lot of changes today and when I just checked, looks like I'm an open relay. I'm sure it's some permissions issue in one of the connectors, I just
don't remember which one.
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Got it, but concern is that in the past, I don't remember if I made any changes to the default connectors.
ASKER
what's the best way to check if any of my settings allow for open relaying?
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Just send an email using PS script from any member server. If it fails, then you don't have open relay.
ASKER
internally, I could send an email, so I know it's open internally.
From member servers?
ASKER
from my own computer, does it make a difference if I run the telnet command from a server or my PC?
To test for open relays, there are many online tools for this.
https://mxtoolbox.com/diag
https://mxtoolbox.com/diag
If you are using script for testing and not passing any credential, And client IP is not added in relay connector, then you have open relay.
ASKER
David:
I used mxtoolbox before numerous times, this is what I get that fails:
SMTP Server Disconnected May be an open relay
But I used 3 other sites, and they all said that it's not an open relay, not sure what to believe.
Amit:
I did not use a script, I just manually did a telnet IP 25
Then just entered sending email, rcpt email, the message and sent.
I did receive the email, so I know internally, it's an open relay, was just trying to figure out it's an open relay externally.
I used mxtoolbox before numerous times, this is what I get that fails:
SMTP Server Disconnected May be an open relay
But I used 3 other sites, and they all said that it's not an open relay, not sure what to believe.
Amit:
I did not use a script, I just manually did a telnet IP 25
Then just entered sending email, rcpt email, the message and sent.
I did receive the email, so I know internally, it's an open relay, was just trying to figure out it's an open relay externally.
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ASKER
I just double checked all the default connectors, and they were all fine, except one, it had the anonymous checked, unchecked it.
Same results on mxtoolbox.
Same results on mxtoolbox.
Wait for sometime, and test again.
ASKER
So I waited a few days, and using wormly.com, it was still able to send a test message, so my system is an open relay :(
All the default connectors are fine, so then I guess it means that one of my other connectors is the culprit, right?
All the default connectors are fine, so then I guess it means that one of my other connectors is the culprit, right?
ASKER
I just realized, wormly.com does not test for open relay, but just tests to see if email is working correctly, send a test email.
I used two other websites, and it can't connect, so I think I'm good.
I used two other websites, and it can't connect, so I think I'm good.
ASKER
Thanks guys for your help.
ASKER
https://www.adminkit.net/smtp.aspx
This place says "550 relay not permitted"
http://www.spamhelp.org/shopenrelay/shopenrelaytest.php
This place says "error, could not connect to server"
https://mxtoolbox.com/SuperTool.aspx?action=smtp%3
This place says "SMTP server disconnected, may be an open relay"
https://www.wormly.com/test-smtp-server
This place says "Message completed successfully.", and I do get the test email.
So who do I trust?