outbound smtp issues in SQL server

Ramanjaneyulu Butharaju 421 Reputation points

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.


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


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


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.


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Accepted answer
  1. Ramanjaneyulu Butharaju 421 Reputation points


    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.


    1 person found this answer helpful.

4 additional answers

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  1. Ramanjaneyulu Butharaju 421 Reputation points

    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.


    1 person found this answer helpful.

  2. Ramanjaneyulu Butharaju 421 Reputation points

    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.


    0 comments No comments

  3. Ramanjaneyulu Butharaju 421 Reputation points

    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.


  4. Ramanjaneyulu Butharaju 421 Reputation points

    yes we have all the above.

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