Occasional error on send email in workflow

  • 1 October 2019
  • 4 replies

Badge +8

Hi there. 


I am finding that lately, workflows that send emails will error with the following:


SourceCode.Workflow.Common.EWS:Autodiscover Failure: THe Exchange server is not available, the password is incorrect or the e-mail address *********** does not exist.  


I would estimate it happens about 20% of the time.  The rest of the time emails send fine.


I've put a ticket in, and it really wasn't helpful.  I tried working with our Exchange folks and we made sure that K2 connects properly with the Exchange load balancer and when we ping the load balancers from either of our K2 servers, they're not blocked.  


At the suggestion of K2, I also ATTEMPTED to change my connection string using the Connection String editor to ping a specific server instead of the load balancer, but it just locks up when I try and gives me an error saying it can't connect to the database.  


So, as a secondary question, is anyone able to use the Connection String editor with K2 5.x?  I read in another forum that this tool does not work on any version past 4.6, but I'm not 100% sure on that.  


Anyway, thoughts are appreciated.  




4 replies

Badge +9

Hi Robert_Nicholas


See the articles below:









Badge +8



Thanks for the prompt reply.


This TLS 1.0 thing did NOT come up in my correspondence with K2 technical support on this issue.


The article only references TLS 1.0...looking at our server we have 1.1 and 1.2 installed and they're both enabled.  Do you know if there is anything futher on this?



Badge +9

Hi Robert_Nicholas


1. Check you firewall if is not the one that is causing this issue


2.See some of suggested answers that resolve this issue below:


Notice this error in customer's HostServer logs:-
"Mail send failure: EWS URL is not valid. Verify the connection strings are correct. Exception: The request failed. The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel."
This is inline with the IE behavior where it will throw the certificate screen when we enter the EWS URL into the IE Browser from K2 Server.

Customer get around this by adding SMTP entries via Connection String editor.


3. changes had been made to TLS and firewall causing K2 to be unable to connect to exchange. this issue has been addressed and K2 was able to re-establish connection to Exchange.


4.Ensure the EWS url being used is correct and that it tests successfully (Test button) on K2 setup manager. They was discover the connection wasn't stable at all. They have since rectify the problem and now didn't getting the errors.




We're not having the exact same issue, but have had the following issue where K2 isn't able to connect to EWS.  After 3 attempts it logs an error to the K2Logs, but the workflow continues as if it was successful.  I'm wondering in your scenario if the workflow goes into error or if it continues on successfully?  I have a ticket open with K2, however they are using a "fire and forget" approach to emails and although the email failed to send, the workflow will continue running as if no issues occurred.  Other than the following entry in K2 logs, no record of this email failure is recorded, so users think the messages were sent successfully.


"2426780923","20*personal details removed*:52:26","Error","General","1","GeneralErrorMessage","EwsMessageDestination","1 The Exchange server is unavailable. Attempting to retry","anonymous","","SERVER:C:Program FilesK2Host ServerBin","2426780923","49fb9e1dfb76446c808c6044460ca449",""
"2426781109","20*personal details removed*:52:44","Error","General","1","GeneralErrorMessage","EwsMessageDestination","1 The Exchange server is unavailable. Attempting to retry","anonymous","","SERVER:C:Program FilesK2Host ServerBin","2426781109","ed3d81a34cea4dcc95c0855bfd302e12",""
"2426781896","20*personal details removed*:53:00","Error","General","1","GeneralErrorMessage","EwsMessageDestination","1 The Exchange server is unavailable. Attempting to retry","anonymous","","SERVER:C:Program FilesK2Host ServerBin","2426781896","a3dde07a7a7943188e22c69fa7f437c4",""
"2426784672","20*personal details removed*:53:18","Error","General","1","GeneralErrorMessage","EwsMessageDestination","1 The Exchange server is unavailable. Attempting to retry","anonymous","","SERVER:C:Program FilesK2Host ServerBin","2426784672","2eb5e317ebb2498fbedc84f6d8180e6c",""
"2426794283","20*personal details removed*:53:27","Error","General","1","GeneralErrorMessage","EwsMessageDestination","1 SourceCode.MessageBus.EwsDestination: Email Send Result False after 3 tries","anonymous","","SERVER:C:Program FilesK2Host ServerBin","2426794283","6c4ae753cdf546d09b9b10f38661de7b",""