Warning: The remote SMTP service does not support TLS. RRS feed

  • Question

  • User1373366444 posted


    in the Event Viewer of the IIS server I find Warnings of the type:

    "Message delivery to the host 'XXX.XXX.XXX.XXX' failed while delivering to the remote domain 'xxxx ****.' for the following reason: The remote SMTP service does not support TLS.The SMTP verb which caused the error is 'STARTTLS'. "

    EventID: 4007

    Configuration of the Virtual Servers of the IIS is correct, I think, but some domains do not reach the mails.

    Any suggestions?


    Wednesday, July 10, 2019 12:24 PM

All replies

  • User-848649084 posted


    To resolve this issue you could try below steps:

    Open iis server select smtp->Properties of the SMTP virtual server, Access tab, Authentication
    button, uncheck "requires TLS encryption"

    Go to the delivery tab->select outbound security->uncheck the "tls encryption"

    Restart the SMTP server after doing changes.

    If still, it is failing than enable logging of the SMTP server.



    Thursday, July 11, 2019 5:51 AM
  • User1373366444 posted

    Hi Jalpa

    if another domains need TLS encryption and I unchecked in Outbound Security, what will occur?

    We should send in two cases.


    Monday, July 15, 2019 1:50 PM
  • User-848649084 posted

    To disable tls for only one domain you can select the domain name from the iis->right click on domain name->select properties.

    than select outbound security.in outbound security uncheck the TLS encryption. 

    Wednesday, July 17, 2019 7:15 AM