Error: The operation 'CAPABILITY' terminated



We are seeing below error frequently (at least few times in a day) when we reading the mails.

The operation ‘CAPABILITY’ terminated. Timeout ‘100000’ has been reached.-The operation ‘CAPABILITY’ terminated. Timeout ‘100000’ has been reached.

Stack Trace:
at Aspose.Email.Clients.Imap.ImapClient.BeginSelectFolder(IConnection connection, String folderName, Boolean readOnly, AsyncCallback callback, Object state) at Aspose.Email.Clients.Imap.ImapClient.SelectFolder(IConnection iConnection, String folderName, Boolean readOnly) at Aspose.Email.Clients.Imap.ImapClient.SelectFolder(String folderName)

Can you please suggest what needs to be done to fix it?



Can you please share source files along with sample code so that we may further investigate to help you out.


This is the code I use and it works all the times, suddenly the above mentioned error comes up. Is there limit in processing the number of emails?

        License license = new License();
		ImapClient oClient = new ImapClient();
        oClient.Host = oRow["SMTPSERVER"].ToString().Trim();
        oClient.Username = oRow["USERNAME"].ToString().Trim();
        oClient.Password = oRow["USERPASS"].ToString().Trim();
        oClient.Port = Convert.ToInt32(oRow["SMTPPORT"].ToString().Trim());
        bool bSSLEnabled = Convert.ToBoolean(oRow["ENABLED"].ToString().Trim());
        if (bSSLEnabled)
           oClient.SecurityOptions = SecurityOptions.Auto;


        ImapQueryBuilder builder = new ImapQueryBuilder();


        MailQuery oQuery = builder.GetQuery();

        ImapMessageInfoCollection messageInfoCol = oClient.ListMessages(oQuery);
		for (int i = 0; i < messageInfoCol.Count; i++)
			MailMessage oMsg = oClient.FetchMessage(messageInfoCol[i].UniqueId);
			//save oMsg object details to DB



I have observed the issue shared. We are internally working over it and will get back to you with feedback as soon as possible.



I suggest you to please try setting Timeout property to some large value or -1 on your end. I also suggest you to please share a test account reproducing issue on your end as well, so that we may further verify issue on our end.


Is the Timeout link mentioned in above post valid? I couldn’t able to access it.



Yes, this link is valid and i am able to access this. can you pleas share what kind of problem you are facing when you tried to access this.


I can able to access it today, I was getting 404 page error yesterday. Thank you.

“Timeout value can not be less then value of NetworkTimeout property”

What is the meaning of above statement wrt. NetworkTimeout?



It’s good to know things are fine on your end.

I have shared the solution with you already for setting the TimeOut value in my previous post as well.


I understand.

I have given the Timeout is -1.

But the below link says the property description as “Gets or sets the timeout for mail operations Please note: Timeout value can not be less then value of NetworkTimeout property”

I was trying to understand the part “Timeout value can not be less then value of NetworkTimeout property”. Can you please explain?



Please disregard this information as its obsolete. We will be removing this in next version too.


Ok Thank you.

I will set the mail client Timeout as -1

I hope this will not cause any other problems and solves the current ‘CAPABILITY’ terminated issue.



Yes, I hope it will resolve the issue.