Email delay on exchange server 2013


  • Hi Team,

    I am running exchnage server 2013 the CAS and mailbox roles are running on different servers, i have 2 mailbox and CAS server in PR site and 1 mailbox and 1 CAS server in DR.

    recently i have seen users complaining about emails delay, i found that not always, but sometimes there is delay in emails, by 2 to 3 minutes,

    hi checked for the event log, to check if there is any logs related to back pressure i checked for event id 15004,15005,15005,15006,15007 on all the servers but cannot find any logs .

    what else could cause the email delay?

    TechGUy,System Administrator.

    Friday, November 10, 2017 9:39 AM

All replies

  • Hi,

    Depends on how your Exchange is setup and network connectivity, you can try below :

    1. Ping your CAS server in DR Site from Site 1 CAS and check reply time (-t as well to monitor for a couple of mins)

    2. Check event log corresponding to the transport services on all your Exchange servers

    3. Send an smtp email from SRV1 in Site to SRV2 in DR site and determine slowness

    Further to this, you can share information regarding your network\exchange connectivity.


    Friday, November 10, 2017 2:02 PM
  • i would get the delayed email as an attachment and would read out the headers to find out the delay. You can find it is between the hub transport of remote sites. Could be due to network congestion, there is a delayed handover of emails

    Always analyze headers first to begin troubleshooting a delay in email

    Thanks & Regards Ramandeep Singh

    Saturday, November 11, 2017 7:59 AM
  • Hi Gudakesh,

    I have no issues with DR, i just mentioned to clear a clear picture of the the environment, there are no active mailbox running in DR, all the mailboxes are active in primary site and the delay is within primary site.

    TechGUy,System Administrator.

    Sunday, November 12, 2017 3:39 AM
  • Hi,

    Thanks for posing in our forum.

    Could you please help to verify the following questions? :

    Does this issue just affect the message external or internal or both?

    Please post out the message header of a delayed message for further troubleshooting.

    Does the affected message with large size of attachments?

    Thanks for your effort.


    Jason Chao

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

    Monday, November 13, 2017 3:27 AM
  • check the header of a delayed email to find out the path of the delay.

    Thanks & Regards Ramandeep Singh

    Wednesday, November 15, 2017 9:42 AM