I am getting ImapResponse Exception Lookup failed m79mb41500705ivm randomly. I am unable to identify the reason. Please help
This is the server side error - this message is generated and send to you be the server. All ImapResponseExceptions indicate error returned by the server.
Most likely credentials you provided are incorrect (user lookup failed).
How does the log look like: https://www.limilabs.com/blog/logging-in-mail-dll Does it reveal any more details?