exact implications of regular notice

Every time I log on to my account to read messages a notice comes up (cannot satisfactorily get large screenshot of it) which is headed Operations and continues connection to my email address… failed.
Underneath   (POP3) An attempt  etc etc  and can be caused…incorrect settings.
At base of box is      ignore all  and hide boxes. Now the messages are coming through if slowly after I log on but what does this Operations pop up mean, it must come up each time for a reason. Thank you for any help here.

Yes, that is an error popup. Some would advise to disable the popup, but maybe figuring out the cause of the error will be more helpful.

One thing you can check is that you have the correct POP3 settings. Go to Menu > Tools > Accounts and click on the POP3 tab. Make sure you have port 995 and the security policy is set to Use SSL/TLS on special port (legacy). Then see if the errors are still appearing.

Have done this, many thanks and will see over a day or so. Was set to 110.

Today, having altered to 995, I could not receive my mail until I changed back again to 110. Diagnostics  page in Operations could not fix this until then. Is there always a delay in the messages arriving. With Outlook Express they were sat there when logging on in the morning?
Also, another issue, I find that when going down a list of messages and deleting one by one, sometimes further messages down the list are deleted to trash also without me getting to them. I am getting old but strange to me.

Disable your anti-virus application and try again using port 995 and the security policy set to Use SSL/TLS on special port (legacy).

Unless it is IMAP, then you want port 993 and the security policy set to Use SSL/TLS on special port (legacy).