question

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RamanjaneyuluButharaju-8253 asked KaelYao-MSFT commented

outbound smtp issues in SQL server

Hello all,

We have MS sql database which regularly sends the mails to internal office 365 users.

From last two weeks its not working and we have not changed anything from server side.

below are the settings.

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when i sent the test mail with above settings we are facing issues and below is the error.

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We have checked windows firewall and port 587 allowed in outbound rules.
We have checked with network team and they have allowed in firewall port 587.

But when i tried telnet to smtp.office365.com 587 from SQL DB machine , below is the result

120442-image.png



Even we have allowed in windows and network firewall still we are unable to telnet smtp.office365.com 587.

turned off windows firewall
allowed any ports in network firewall.
Uninstalled Mcafee antivirus from machine totally


still same issue ??
We are out of ideas tried everything we thought but still we are unable to understand the issue.

Please help.



Regards,
Ram

sql-server-generaloffice-exchange-server-administration
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· 2
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SQL Server is a SMTP email client as any other email client like Outlook; so the issue isn't SQL Server related.
And if even TelNet don't work, then it must be an issue on the way from client to email server.

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yes, I don't think any issue with SQL.

even tried to send the mail from PowerShell script still facing issues.

Here is the result,


120444-image.png


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RamanjaneyuluButharaju-8253 answered KaelYao-MSFT commented

122659-image.png



BTW Besides, are you using dynamic ip addresses for your server? : No we are using static IP for server.

As an update, we have asked Security and Network team to Investigate why it is blacklisted.

we got an update from network team today to check the mails now.

Now everything seems working fine.

Network Team asked ISP vendor to check why those IP are in blacklisted and ISP vendor did something in backend.

At present we have asked ISP vendor to provide the RCA than we get to know why those are blacklisted.



Regards,
Ram


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You likely have an open SMTP relay on your network somewhere and an outsider is using your network to spam people.

It is never a good idea to relay your email to an outside SMTP server. You should always use your own SMTP server to prevent this problem from happening.

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Glad to hear currently the issue is gone.

Thanks in advance for your update.

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RamanjaneyuluButharaju-8253 answered RamanjaneyuluButharaju-8253 commented

This issue is resolved after changing the ISP in network firewall.

Might be an issue with ISP blocked office 365 or office 365 blocked my ISP.


Regards,
Ram

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Hi Ram.

Glad to hear the issue has been resolved!
Thanks for your sharing.

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Seems the issue popup again.

It was worked until yesterday morning and again same error.

Tried changing the public ip in firewall but no luck.

Raised the case with Microsoft Support team.

Regards,
Ram

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RamanjaneyuluButharaju-8253 answered

As an update, Microsoft support checked the public IP is listed on their blocked list
yes one of my public ip is listed there for the reason of mass sending mails(might be).

They asked us to delist the IP from here : https://sender.office.com/

As of now its been 4 hours, still its not working.


Regards,
Ram

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RamanjaneyuluButharaju-8253 answered KaelYao-MSFT commented

As an update, we have delisted but still its not working..
Support team advised to check is those my public ips is in blacklist of mx tool box.
And yeah, both my public is listed there..
I don't know what to do now.

Regards,
Ram

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Hi Ram.

I would suggest first finding out which blacklist you are in and why are you in the blacklist.
Have you setup SPF/DKIM/DMARC records for your domain?

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RamanjaneyuluButharaju-8253 answered KaelYao-MSFT edited

yes we have all the above.

why are you in the blacklist > how do I find that ?

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Hi,

Can you find some information like which blacklist you are on via the mx tool box site?
Better contact those who are in manage of the blacklist to confirm why you are in the blacklist.

Besides, are you using dynamic ip addresses for your server?
It should be a normal cause of being blacklisted as dynamic ip addresses would often be used to spam.

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