Hi when I'm crating an email account shows this error

P.S

The email account creates but the panel shows SolidCP ERROR

https://domain/error.htm?aspxerrorpath=/Default.aspx

Event code: 3005
Event message: An unhandled exception has occurred.
Event time: 11/10/2017 1:19:58 PM
Event time (UTC): 11/10/2017 12:19:58 PM
Event ID: 16df80d093024b12a534c20c6b51f851
Event sequence: 219
Event occurrence: 2
Event detail code: 0

Application information:
Application domain: /LM/W3SVC/4/ROOT-2-131547756339246285
Trust level: Full
Application Virtual Path: /
Application Path: C:SolidCPPortal
Machine name: *

Process information:
Process ID: 2560
Process name: w3wp.exe
Account name: *SCPPortal

Exception information:
Exception type: WebException
Exception message: The remote server returned an error: (404) Not Found.
at System.Net.HttpWebRequest.GetResponse()
at Knom.Helpers.Net.APIMailCleanerHelper.APICall(String f_stParam, Int32 f_iPlanID)
at Knom.Helpers.Net.APIMailCleanerHelper.DomainAdd(String f_stDomain)
at SolidCP.Portal.MailAccountsEditAccount.SaveItem()
at System.Web.UI.WebControls.Button.OnClick(EventArgs e)
at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument)
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

Request information:
Request URL: https://*:443/Default.aspx?pid=SpaceMailAccounts&mid=102&ctl=edit_item&SpaceID=26
Request path: /Default.aspx
User host address: 46.99.154.137
User: serveradmin
Is authenticated: True
Authentication Type: Forms
Thread account name: *SCPPortal

Thread information:
Thread ID: 3420
Thread account name: *SCPPortal
Is impersonating: False
Stack trace: at System.Net.HttpWebRequest.GetResponse()
at Knom.Helpers.Net.APIMailCleanerHelper.APICall(String f_stParam, Int32 f_iPlanID)
at Knom.Helpers.Net.APIMailCleanerHelper.DomainAdd(String f_stDomain)
at SolidCP.Portal.MailAccountsEditAccount.SaveItem()
at System.Web.UI.WebControls.Button.OnClick(EventArgs e)
at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument)
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

Custom event details: