I have two email accounts. One with Gmail and one hosted by 1and1 using IMAP.
Both accounts worked fine until yesterday.
Then Today I found out that although the IMAP account appeared to work OK no-one was receiving my emails.
I then checked from my Laptop which has a near identical setup.
It worked OK.
I then disabled "Email Protection" on my desktop and then Emails were sent/received ok (I am checking by sending to my other email account) - and continue to be received by my clients. None of the emails I sent yesterday were received.
Investigating further I found my Laptop is still running Version 19.9.0.9 and my desktop is running 20.2.0.19.
So being brave I upgraded my Laptop Norton to 20.2.0.19 thinking it might then prove the upgrade was the issue. However it still works fine on the Laptop
I checked again on the Desktop and still emails not being sent if use "Email Protection " turned on.
While looking into this I found a problem when I had Google Chrome Browser installed - Norton always tries to use IE10 even though Chrome is the default browser. I solved this by uninstalling Chrome and changing to Firefox as the default browser)
So
Now all working OK but I must have "Email Protection" turned OFF.
Help Please as I would rather have the Email Protection turned on.