none
Huge Delay receiving emails and sometimes no emails

    Question

  • Hello, we have Exchange DAG cluster 2016, symantec messaging gateway is providing the spam filtering with Huawei as our firewall. We have a single leased line with multiple IP addresses among which we chose one for Exchange server and port 25 is forwarded to symantec and 443 to exchange.

    The problem is we have huge delays receiving emails from may of our clients, sending email from gmail, hotmail, yahoo, works just fine. But our clients are unable to send any. But they receive just fine from us.

    I have checked spf, mx, dns, everything resolves normally.

    we even forwarded 25 directly to exchange bypassing symantec, but still the same. All of a sudden it starts sending all the emails and most of the working hours it doesn't send us any. 

    No Non delivery report or anything. I checked in symantec but no email flow is there. I dont know where it is going.

    Can anyone help please

    Sunday, March 4, 2018 2:55 PM

All replies

  • So it internal has no issue right? This will mean your gateway is the cause. Did you check things like allow relaying from Exchange to the gateway or check if the IP of the Exchange is block?

    Can you see the email leaving the gateway?

    • Edited by Michael Vi Monday, March 5, 2018 12:12 AM Edit
    Monday, March 5, 2018 12:11 AM
  • Hello,

    Thanks for contacting our forum.

    Have you create specific receive connector for your clients? If so, it's recommended to recreate it and check the results.

    From your description, there's no SMTP sessions through symantec, it seems the sender's IP address has been blocked, how about bypassing symantec then check if any SMTP log on the Exchange server side.

    Hope it helps.


    Best Regards,
    Jason Chao


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.


    Click here to learn more. Visit the dedicated forum to share, explore and talk to experts about Microsoft Teams.

    Monday, March 5, 2018 7:07 AM
    Moderator
  • Hello,

    No we dont have any specific connectors, as i have mentioned earlier we even bypassed the symantec messaging gateway. But the issue still exist

    Tuesday, March 6, 2018 6:12 AM
  • Thanks for your response.

    Could you please post out the message header of the delayed message? We need to check in which step the messages have been delayed.

    We can also use the message header analyse tool: https://testconnectivity.microsoft.com/

    Hope it helps.


    Best Regards,
    Jason Chao


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.


    Click here to learn more. Visit the dedicated forum to share, explore and talk to experts about Microsoft Teams.

    Friday, March 9, 2018 1:44 AM
    Moderator