Hi RayFor,

Usually, we will recommend checking the Host Server logs as the actual error causing the mail send failure will be surfaced there. See if this other article might help:

https://help.k2.com/support-services/kbt142384

Hi,

I suggest checking what  @lkimberly mentioned in previous post. I would add that the issue can happen when K2 service account doesn't have an valid email address.

Please go through the two steps below to validate it.

1. Execute the UMUser SmartObject's Get User Details method for the K2 Service Account. (i.e. K2_install_directoryBinSmartObject Service Tester.exe) 

2. Check the mail server and from address variables from default Enviornment Library in K2 Management site.

hi  @khanh 

Thanks for your help. We found the root reason is that the Exchange Server config the receive policy so we changed the policy then resolved the problem.

Best regards,

Hi,

We are receiving the same problem, I don't suppose you could elaborate further on this solution?

Thanks

As a follow up if anyone else experiences this issue the solution for us was to install the latest Fix Packs. Once these were installed the problem was resolved.

Thanks
Nathan

hi sir,

May I know the details on your solution?