Invalid Credentials Temporarily Unavailable

[#1]

I'm trying to add my old free-online mail account to Outlook on my new Windows 11 computer.

I have used my user name and password and what I think are the correct entries for POP3 as follows.

Incoming Server -  mail.free-online.net Port 110 Secure Connection- none

Outgoing Server relay.free-online.net Port  25 or 143, I tried both Secure connection - none

It then askes to Sync the POP Account to the Cloud then says waiting for your email provider.

After about 30secs there is the message - Sign in fail - you may need an app password.

Selecting the Trouble shoot button reveals the message "Invalid Credentials Temporarily Unavailable"

The nice guys at PlusNet help were unable to help, hopefully someone out there has come across this problem and can help me.  I would be very grateful.

[#2]

@Murus use the Email troubleshooter here https://community.plus.net/t5/Email/Diagnosing-email-server-connectivity-issues-the-guide/m-p/200795...

Try with both your username OR full email address and report the results

[#3]

Free-online should use account or account+mailbox

smtp server is always port 587 with STARTTLS.

Requiring an app password does not apply to any Plusnet mail service.  It is though relevant to configuring an outlook.com email address for the first time.

Is this proper outlook (Microsoft 365) or outlook via a web browser?  If 365, where is outlook storing its PST files.

If this mail box is to be accessed from multiple devices, do not use POP3 … doing so just creates complications.