Plusnet POP3 server login, same client, one works the other fails

[#1]

I have a free-online email only account associated with my john lewis broadband account. Both email accounts are accessible by webmail. The free-online account works perfectly with POP3 (thanks Gandalf) but I have never been able to log in to the server using my john lewis credentials. This is the response:

[*] Connection established to 212.159.9.37
>> 0018 +OK Hello there.
<< 0019 USER <<redacted>>
>> 0024 +OK Password required.
<< 0016 PASS XXXXXXXXX
>> 0020 -ERR Login failed.

The client is Pegasus Mail running under Wine on Linux Mint. Port is 110 on both. I have a wireshark dump that shows the username and password are transmitting correctly as plaintext. JL tech support have batted this around with canned advice and are now telling me that they don't support Linux and because webmail works it must be a client problem. Can someone please investigate what is different between the servers:

mail.free-online.co.uk and mail.johnlewisbroadband.com

I am quite willing to give Thunderbird a try but I would really like to know why the login fails.

Regards, JeffH

[#2 · Accepted solution]

I set up Thunderbird as a client for both email accounts. Having checked the free-online access I then exhaustively worked my way through every imaginable POP3 setting. It took a while. The good news is that I found the problem. The free-online POP3 login uses only the username "MyFreeOnlineUserName". The JL POP3 login requires the FULL email address "MyJohnLewisUserName@john-lewis.com" as the username. The mistake should have been obvious to anyone who analysed the transcript I sent to JL when this all began over 6 weeks ago. (Not so from my post here because I redacted the username). So I am pleased to have sorted it but very disappointed that the team did not understand technology which has been around for over 25 years; and excuses themselves because of my OS/client software. Regards, Jeff