There are hundreds of people posting this problem but I think my situation is different.
Yesterday morning Outlook was sending and receiving email with no problems. It has done that for the past 3 years, though occasionally I did get the error code but on retrying the problem went away.
Yesterday though, about two hours after I booted up, email retrieval stopped. I kept getting the error message all day. I restarted multiple time, checked all the ports, etc, but the problem kept up. I can send emails, but could not receive. I was able to see my incoming mail only by going to my ISP's web site and looking at it there.
I shut down for the night.
This morning I booted and started Outlook. To my surprise I found all of yesterdays emails were now in my inbox. I was overjoyed, but only briefly. I sent an email with no problem. But then I noticed that Outlook was now going out to retrieve incoming emails and it was showing the progress bar, but nothing was happening. Then I got the error message again, and I have kept getting it for the past 3 hours. I have restarted Outlook three times and still have the problem.
What happened that on an overnight shutdown and boot I was able to receive emails, but not after? Obviously my system is configured correctly. Right Ports, SSL's, etc., AND Norton was running before anything else was started.
This problem has existed since 2003 on all versions of Outlook and yet there is no fix from Microsoft. Who do we have to contact there to get this fixed once and for all? None of the answers I have seen on multiple boards have gotten anywhere near to solving the problem.