Problem sending free-online emails

[#1]

Plusnet is my broadband provider and I have had a “free-online” email account for many years which has always worked perfectly using Thunderbird as the mail client with the incoming server set to “mail.free-online.net” and the outgoing smtp server set to “relay.free-online.net”.

Suddenly in mid October I found I could not send emails - getting the 4.3.2 internal server error message. Incoming emails were still being received as usual.

Not knowing what to do I changed (in Thunderbird) the outgoing server to

“relay.plus.net”.This solved the problem and emails were sent OK.

I have no idea why the server has been changed and I was never informed of this. Could it be anything to do with the migration to Greenby. My problems started around the same time as I received an email from Plusnet informing of the planned migration.

I noticed when looking through the forum that several users have had problems with sending emails recently -perhaps changing the server as I did might help.

An interesting by product of changing the outgoing server - even though the incoming remained the same - was that my inbox filled up with hundreds of old emails dating back 4 or 5 years - all of which I had deleted long ago.

Something  very strange is going on with the Plusnet servers - any advice would be much appreciated.

[#2]

There is nothing particularly strange going on.

The issue you describe is related to the questionable practice of not specifying authentication credentials on the outbound server.  Your revision of the settings on your email client will have corrected that bad practice.

[#3]

Thank you for your reply Townman. My email problems have now increased although I have not changed any settings since my first post.

Now I can’t receive any emails either in Thunderbird or Plusnet Webmail but can still send. This receiving problem occurred very suddenly on the 5th November - all was OK up to the 4th.

My free-online email account has worked perfectly for the past 15 years but since mid October has been beset by problems.

I’m no expert in these matters but there must be some changes that have happened outside the environment of my computer and mail client. I can only assume this is with the Plusnet servers as nothing has been changed on my system.

If you or someone could advise me on what servers I need to use and the settings needed in Thunderbird for Connection security and Authentication I would be really grateful.

Thank You

[#4]

Hmmm... what AV software are your running?  AVG or Norton (ideally something else)?

Please can you run the server connection diagnostics (see the link below) and confirm the outcome ... and ...

• Email brand (Free-online?)
• Mailbox - default or secondary
• Inbound email client type (IMAP or POP3)
• Connection on or off the Plusnet network

I have various theories, but I need you to clearly define your environment.

There have been some pre-migration changes.  Have you received a migration notice?

[#5]

Thank you for all your help with this problem. Much appreciated.

I did click on the email diagnostic link but it did not seem to work. I entered my details, platform, user ID etc and it just displayed a mass of general information but nothing specific about my set up?

Your other queries:

There is no AV software on my PC. The OS is Linux which is very secure and stable.

Email Brand: free-online

mailbox: default

Inbound client type: POP3

Server: mail.free-online.net    Port 110

           connection security: none    Authentication method: password transmitted insecurely

Connection on or off the Plusnet network:

Not sure how to answer this -Plusnet is my broadband provider so when using Thunderbird  - my usual method for emails- I assume this is not connected through the Plusnet network other than the servers - but honestly don’t know.

I occasionally use the Plusnet Webmail app which I assume is connected through the Plusnet network. Apart from entering my ID and password I don’t have any control over the settings for Webmail - so it’s interesting to note that this too is not receiving emails at present but always did.

Migration notice:  I did receive an email on 22/10/25 informing of the planned migration which was due to start on 24th November. It stated that this was in respect of mygray@gray64.plus.com. email account and asked if I wanted to opt out of the migration.

This “plus.com” email was included in my Plusnet broadband and phone package and I never use it   - I was not sure what to do but as my main email account is free-online, a Plusnet brand, I thought it better NOT to opt out. Interesting again that this was around the time all my email problems started.

As I can’t receive emails at the moment I don’t know if any further notification has been sent.

BTW I’m going away for a week’s holiday on Sunday so won’t be able to reply or send further info to you until I get back.

[#6]

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@gray77 wrote:

getting the 4.3.2 internal server error message. Incoming emails were still being received as usual.

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Really very sorry ... when I first looked at this issue, I was using my phone and missed this near throw away comment.

This error is specific to SENDING email and the SMTP server configuration NOT specifying authentication details in the Thunderbird client.  Set the SMTP server to use the same credentials as the inbound server.

POP3 really ought to be on port 995 with encryption set to TLS/SSL.

The issue sending with Webmail is likely to be different, I suspect this...

Sender Domain Rejected (black listed by local policy)

This issue can report as server error 550. It typically arises where a user's email address has been abused for the purposes of sending spam emails. It has nothing to do with server settings etc.

This requires intervention by staff to determine the cause of the problem and to issue advice to check your system for viruses and malware. Only after your system(s) have been affirmed to be clean can the black listing be lifted. As a precaution, you should change the password on the affected email address.

Add your details to this thread - Cannot Send Emails and send a PM to @Leanne_T