topic Re: Plus nets Relay server down? in Email

Plus nets Relay server down?

madswitcher — Sat, 30 Sep 2023 12:15:52 GMT

Is anyone having problems with Plusnet's relay server for emails from a non-Plusnet ISP (relay.plus.net)? it looks like the authorisation side of things is not working as it is constantly asking me to re-enter my password - I am coming from YOU and using Thunderbird email client.

Re: Plus nets Relay server down?

phimmies — Sun, 01 Oct 2023 19:29:14 GMT

We can’t send emails from our other faster router, only the plusnet hub works. Something wrong or changed with email server authentication recently

Re: Plus nets Relay server down?

jab1 — Sun, 01 Oct 2023 19:31:13 GMT

@phimmies The router you use has zero effect on your email traffic - provided it is set up correctly.

Re: Plus nets Relay server down?

phimmies — Sun, 01 Oct 2023 19:38:02 GMT

Hi
I beg to differ. If I’m away from home using a non-plusnet connection, I had loads of problems getting the emails to send. I have had it static for many years now and it all works. But this week, from home, (using my 4G router from Three), the emails have stopped sending saying there are “errors with the password settings.” If I swap to my plusnet router, it magically works. I’ve had this setup for 3 years without issues. We are rural so can only get the 5mb copper connection from PN , the 4G was desperation during covid.

Re: Plus nets Relay server down?

jab1 — Sun, 01 Oct 2023 19:45:03 GMT

If you are away from home, or, I SUSPECT, but don't know for sure, using the 4G router, you need to set authentication on in your email program, otherwise, the Plusnet relay will refuse connection.

Re: Plus nets Relay server down?

phimmies — Sun, 01 Oct 2023 20:30:08 GMT

Hi guys. Thanks again. I would like to stress, this has been working for 3 years already. It isn’t one device where this has changed, it no longer working on the iPad nor the iPhone. Only the iPhone had the recent IOS update , so I’m ruling that out. I’m only trying to track down why it’s suddenly failed to authenticate. The port number hasn’t changed, nor has the outgoing server.
I’m due to go abroad for a week so want to ensure I can send emails when away from the home server. If the plusnet techies say the authentication hasn’t been changed, no upgrades to SSL (e.g. TLS 1.2 to 1.3) or any of that jazz, then I’m stumped.
I’m just trying to figure out why it’s stopped working. Sorry if it sounds harsh, it’s been a long week

Re: Plus nets Relay server down?

jab1 — Sun, 01 Oct 2023 20:39:20 GMT

So you have set authentication to 'on'?

You say this is on iPad/iPhone - have you tried rebooting/resetting them, or deleting/re-inserting the accounts - I had this issue a long time ago. Apple kit has some funny habits.

Re: Plus nets Relay server down?

phimmies — Mon, 02 Oct 2023 13:48:41 GMT

Hi John & co. Despite having already rebooted the 4G router, I have done a further one and the issue has “mysteriously” disappeared. Another case of turn everything on and back on …. twice !
Thanks for the support.

Re: Plus nets Relay server down?

MisterW — Mon, 02 Oct 2023 17:50:11 GMT

@phimmies I suspect the problem was a bad reputation of the ip you had been assigned, this would cause relay.plus.net to reject the connection.Reconnecting would eventually get you a different one. Ideally the mail client ought to return the error but I'm afraid many just report an authentication error irrespective.

Re: Plus nets Relay server down?

madswitcher — Wed, 04 Oct 2023 13:41:33 GMT

My problem still exists and is not fixed: my 'old' ISP was Virgin and I seem to remember having significant problems getting that to work initially with relay.plus.net when we started the service with them. We are now parallel running with YouFibre until YouFibre 'settles' down and these glishes are sorted.

Going back to Virgin, sending via SMTP (now) works, but YouFibre still doesn't. So it does appear to be Relay.plus.net blocking requests from YOU.

In case you are wondering, moving to YOU is FFTP, 2G up and down and 2/3 the price of Virgin: pings are a consistent 2mS.

Re: Plus nets Relay server down?

MisterW — Wed, 04 Oct 2023 13:51:04 GMT

@madswitcher can you try the SMTP test as described here https://community.plus.net/t5/Email/No-email-this-morning-10-November/m-p/1831686#M36647 . That way we can get the exact reason for the failure

Re: Plus nets Relay server down?

madswitcher — Thu, 05 Oct 2023 10:01:05 GMT

Eventually this problem was (sort of) cured: I powered everything associated with YouFibre down and up 4 times and tested in between. On the last one I was able to send emails.

I assume, as one reply above suggested, that the problem was something to do with the DHCP IP address that the modem was acquiring was being blocked by Relay.plus.com for some reason.

Anyway, up and running now and thanks for the help.

Re: Plus nets Relay server down?

MisterW — Thu, 05 Oct 2023 10:21:19 GMT

@madswitcher it was almost certainly due to your 'IP address reputation'.

From what I can determine , You Fibre use CGNAT , which means that many people 'share' the same public IP address

https://support.youfibre.com/hc/en-gb/articles/360019701017-Why-does-my-IP-address-change-

We use the Dynamic Host Configuration Protocol (DHCP) to dynamically assign IP addresses (both IPv4 and IPv6) due to the scarcity of IPv4 address caused by the rapid expansion of the internet. We also use Carrier-Grade Nat (CGNAT) for residential premises to efficiently assign our IPv4 address range.

If someone else, sharing the same public IP, has been sending spam, then the IP will acquire a poor reputation. I'm afraid the problem is very likely to reoccur, the only good thing is that the reputation tends to improve after 24h.

Re: Plus nets Relay server down?

madswitcher — Tue, 10 Oct 2023 19:59:31 GMT

Hi again MisterW

as you surmised, the situation arose again this afternoon.

So I followed you suggestion about Telnet to relay.plus.net and got the following reponse after the DOS screen goes blank

"220 avasout-peh-004 smtp relay.plus.net" - almost immediately

then after a couple of seconds

"Connection to host lost"

I also tried using port 23 which is what my SMTP server is set to in Thunderbird and got

"Connecting To relay.plus.net...Could not open connection to the host, on port 23: Connect failed"

Obviously without the quotes. Could you kindly let me know what this means so I can pass the information onto my ISP or is the problem at the plusnet end of things?

Hope this helps to pin it down further. Anything else I need to do?😀

Thanks again

Re: Plus nets Relay server down?

MisterW — Wed, 11 Oct 2023 05:49:50 GMT

I also tried using port 23 which is what my SMTP server is set to in Thunderbird

It ought to be set to port 587.

Did you try telnet to port 587 ?

Re: Plus nets Relay server down?

madswitcher — Wed, 11 Oct 2023 10:47:30 GMT

yes

the first responses I gave you were those due to to telnet 587.

Sorry my mistake, that should have been port 25.

Port 25 is what was in and working in for some years in Thunderbird before the problem started to occur and the problem is indentical for both port 25 and 587

I have tried the same probe again which gave the same response.

220 avasout-ptp-004 smtp relay.plus.net

Connection to host lost.

I have also just rebooted my modem etc and tried the Telnet probe and got

220 avasout-ptp-003 smtp relay.plus.net

Connection to host lost.

I can also now send emails

Any thoughts

Cheers

Re: Plus nets Relay server down?

MisterW — Wed, 11 Oct 2023 11:06:17 GMT

The server is timing out because you are not sending EHLO

Mail is probably sending again because you have a different ip or the reputation of your existing one I proved.

I suspect its going to be a consistently intermittent problem...

Re: Plus nets Relay server down?

martinwalton — Wed, 17 Jan 2024 22:49:34 GMT

Hello MisterW

I've been seeing this issue intermittently for a long time and it's very annoying. I'm using Thunderbird and relay.force9.net on port 587. It refuses to work at all one day, and is completely fine the next.

It sounds like you know why this might be happening - can you go into more details or suggest a fix please.

Thanks

Martin

Re: Plus nets Relay server down?

MisterW — Thu, 18 Jan 2024 07:18:29 GMT

@martinwalton when it fails , try the test described here https://community.plus.net/t5/Email/No-email-this-morning-10-November/m-p/1831686#M36647

That will give the exact reason for the failure. The problem with email clients is that they tend to hide the real reason for failure and rather just report 'failure to send'.

Re: Plus nets Relay server down?

Townman — Thu, 18 Jan 2024 17:33:44 GMT

@martinwalton wrote:

It refuses to work at all one day, and is completely fine the next.

Martin

Hi Martin,

That is very symptomatic of having picked up a bad (dynamic) IP address ... and then having picked up a clean one. The test set which @MisterW point you to will disclose the cause of the authentication failure condition.

You do not indicate how your device is connecting to Plusnet's mail servers...

Plusnet supplied internet
Mobile network
Some other ISP's network

If it is a Plusnet supplied connection, have you noticed any restarts on the router - such has a fair chance of changing your (dynamic) IP address which can give rise to the symptoms you report. If the connection is third-party, then there is a higher chance that you have been swapping IP addresses but are quite unaware of that.