Email routing issue limited to BT Server 212.159.9.200 ?

[#1]

Problem intermittent for last three weeks. Outgoing emails to T-online (Deutsche Telekom) hang in Outbox with a local prompt to check SMTP servers. Return emails from t-Online not arriving. Sender advises me that messages are bounced at 212.159.9.200 . BT's international servers?

Messages from Gmail and iCloud are sent and received as usual. These don't access the BT servers at the address mentioned above?

Tech Support suggest it's overloaded mailboxes. This is doubtful since I have term settings to delete messages but anyway I cleared down to approx 30Mb. Problem still persists.

Any ideas on how this might be fixed will be appreciated. AB

[#2]

Which outgoing SMTP server are you using? For Plusnet customers this should be relay.plus.net using port 587. SSL/TLS needs to be set to "off" (or "no"). Authentication is needed if you are not using your home connection.

Messages sent to you should be passed to mx.avasin.plus.net which has the IPs 212.159.8.200 and 212.159.9.200 (the one mentioned in your post). These are Plusnet servers, not BT's. If emails are being bounced the sender will receive a non delivery report. You need to ask them for the full text of that report to understand the reason for the bounce.

[#3]

Thanks for responding. The bounced message: .....Host MX.AVASIN.Plus.net  IP 212.159.9.200 (said 550# 5.1.8)

I can't see a port number. I assume it's 25  because I used auto set-up for the Hub One. I've tried system preferences/ Email accounts, any any number of possible routes find the actual port number. Authentication is OFF.The SMTP setting is relay.plus.net.

Does this make anything clearer?

(I guess that PN's servers are listed under BT in some tables? It is on the AVASIN site)

Thanks again, AB

[#4]

In the bounced messages what text follows the 550# 5.1.8 string? Is it "domain of sender does not exist"? Or something different?

For sending emails the port number has no connection with how you router is configured. It would be one of the settings configured in your email client (possibly shown in an "advanced" section if there is one. What email programme (client) are you using, and are you using this on a PC or mobile device connected to the internet via your router?

[#5]

Thanks for your response.

The subsequent information is  "domain of sender address ********@t-online.de.  ( **** = the name of the sender)

Should there be more information attached?

This problem appears now to be limited to this receiving email account/server because other emails  to and from Germany on an alternate address, not t-online, are OK.

I'm sorry if this is somewhat incoherent, but I hope it's useful.

Thanks again for your help. AB

[#6]

After that sender address it probably says "does not exist". This might appear on another line.

Clearly it is nonsense to claim that t-online.de does not exist - but to be sure I've checked and DNS says it does (exist).

I think what you are seeing is another instance of the problem(s) covered in the long topic Plusnet Email servers giving random SMTP 550 errors for inbound emails which started in November 2017 and fizzled out in June 2018 without a recorded resolution as far as I can see.

I'll follow it up with Plusnet staff tomorrow.

[#7]

David, Thank you. I'm slightly reasssured that it's a wide-spread issue and not down to me.

In my search for the outgoing port I noticed that the log on my Hub One is showing a rash of "tcp reset attack suspected".

I don't wish to muddy the water but wonder if it's relevant? Or a side-effect?

AB

[#8]

The outgoing port for your email won't be found in your router settings. It's a configuration setting when you set up your email account in your email program/client. You use this client when you view and send emails. Typical names for this are Outlook and Thunderbird, or just Mail if it's the app provided with Windows 10.

The entries you spotted in your router log sound bad but they reflect its firewall doing its job to prevent unauthorised access. There could be batches of these but they shouldn't go on for ever. Do they? I wouldn't expect them to have any connection with your email problems.

[#9]

Yes, Port info hidden behind automatic connection function on Mac Mail. I eventually discovered.

Anyway Happy Days.. just received this scammimg email.... "Unusual Login Attempt from Plusnet Support" Note typos and odd grammar.

[#10 · Accepted solution]

Thanks for taking the time to respond. The problem remains.  Raising the matter with tech support resulted in unacceptable delays in responses and  consequently I decided to close the account and go elsewhere.

The Plusnet business model is low tariffs and high churn rates. The bare bones email offering, paucity of technical and customer support staff coupled with the promotion of the "Community" tells the story.  As does the continual TV ads.

But thank you for your independent support.