topic Re: SMTP gateway issue in Email

SMTP gateway issue

lyndonp — Wed, 28 Sep 2022 14:28:40 GMT

Currently can’t send any Plusnet emails out through the SMTP gateway at the moment. Been like this since this morning.

Can’t see any response from any Plusnet staff.

Can we have an update please as to what the issue is and when it will be restored.

Re: SMTP gateway issue

MisterW — Wed, 28 Sep 2022 14:46:15 GMT

@lyndonp just tried from my account and can send no problem.

Has anything changed in your email client settings ?

Can you send from webmail ?

Re: SMTP gateway issue

lyndonp — Wed, 28 Sep 2022 14:48:15 GMT

Just noticed a test I setup from Plusnet account through the PN gateway which was failing and was still in my Outbox has just arrived in my gmail account.
Done a couple of tests and going through now.
Will it stay up or is there an intermittent fault?

Re: SMTP gateway issue

lyndonp — Wed, 28 Sep 2022 14:50:21 GMT

Nothing had changed it my settings. Also my son was having the same issue and he hadn’t changed his settings. Don’t know if his is working yet.

Was definitely a Plusnet gateway issue since this morning but as I say it is working now which is probably why yours went through.

Re: SMTP gateway issue

MisterW — Wed, 28 Sep 2022 14:57:31 GMT

I would have thought if it as a general problem there would have been more posts on the forums and there's nothing showing on the Service status ( but then again that's not unusual! ). I must admit, I haven't sent any email via the PN servers today, up until I just tried the test

Re: SMTP gateway issue

Total_Chaos — Thu, 29 Sep 2022 09:17:14 GMT

I have seen this occasionally. However it is often resolved by restarting email client, computer, and router though checking between each restart. However, very occasionally having done this it still won't go so leaving an hour it will start. PN's status shows no issue, and using webmail works. It is not necessarily a PN issue as we go through many devices to reach the PN mail gateways and the issue could be enroute.

Re: SMTP gateway issue

lyndonp — Thu, 29 Sep 2022 09:58:39 GMT

Was odd, I first noticed it around 10am when I was out and about using 4G (Plusnet mobile).

Got home connected to wifi (Plusnet) and still the same issue.

What I did do was switch my smtp settings to the alternative 587 from 465 but that made no difference. I then posted on here and the test email in my Outbox went through shortly afterwards!

My Inbox emails also all disappeared just before i changed the Smtp too even though they had been coming through during the day ok. Can’t remember if I restarted my email app (iPhone) or they all came back on their own but I’ve seen that issue before and restarted app to fix it.

Like you I have had rare issues on the wifi needing to restart the router but since I replaced the PN router with the BT Home hub after seeing folks on here recommend it I have never needed to do that.

BTW, My son’s issue was a totally different issue and not the same it turned out. Just coincidence!

Re: SMTP gateway issue

Townman — Thu, 29 Sep 2022 12:56:58 GMT

When attempting to send and it fails, exactly what are the circumstances?

What is the device
What mail program is being used
How does it connect to the internet (mobile / wifi / on or off the Plusnet network)
What error message do you see
How do you know that it was not sent (stuck in the outbox or it did not arrive with the addressee - those are quite different issues)

If you are sending from a PC, you might care to use the following SMTP diagnostic to find out precisely what is happening.

Test SMTP authentication

Email programs often report username / password error for issues not actually related to those being wrong, but for other connectivity issues. Such can be very frustrating when you are convinced that they are correct. Testing SMTP authentication through a command line interface can deliver a more precise error message. The following describes how to do this using TELNET.

This is not difficult, but you need the following resources which might be unfamiliar...

TELNET - this might need installing as an additional option, for Windows see enabling TELNET.
A code64 encoder / decoder such as this.

You can use TELNET to communicate direct with the SMTP server as follows...

Open the code64 encoder in a web browser and leave ready for use in the following steps.

Launch a windows command line window (DOS window) - press windows-key+R - type CMD into the run box - click OK

Enter...

telnet relay.plus.net 587

Press enter. Note if you use one of the other brand email services, use the appropriate SMTP server name for that brand. In response to SMTP server I'm here message, say 'HELLO'...

EHLO relay.plus.net

The SMTP server will then report what it can do after which tell the server you wish to authenticate...

AUTH login

The server should return the following, which is a base64 encoded string that requires your username:

334 VXNlcm5hbWU6

Use the code64 encoder to encode your username and paste it into the telnet window and press enter. For example:

bXl1c2VybmFtZQ==

The server should return the following, which is a base64 encoded string that requires your password:

334 UGFzc3dvcmQ6

Paste the base64 encoded password for the username. For example:

bXlwYXNzd29yZA==

The server will then report success or failure, any failure message should clearly indicate the reason for the failure. If the reason for the failure is not clear, please report back the message.

Close the SMTP / TELNET session by entering

quit

The session should look something similar to the below wherein your input is in bold...

220 avasout03 smtp relay.plus.net
EHLO relay.plus.net
250-avasout03 hello [your IP address], pleased to meet you
250-HELP
250-AUTH LOGIN PLAIN
250-SIZE 104857600
250-PIPELINING
250-8BITMIME
250-STARTTLS
250 OK
AUTH LOGIN
334 VXNlcm5hbWU6
bXl1c2VybmFtZQ==
334 UGFzc3dvcmQ6
bXlwYXNzd29yZA==
235 ... authentication succeeded
quit
221 avasout03 smtp closing connection
Connection to host lost.

Here are some examples of failure responses...

535 ...authentication rejected [as username / password is wrong]
535 ...authentication rejected as source IP has a poor reputation
535 Too many SMTP auth failures. Please try again later.

Re: SMTP gateway issue

Total_Chaos — Thu, 29 Sep 2022 14:15:50 GMT

Re: SMTP gateway issue

Townman — Thu, 29 Sep 2022 14:49:43 GMT

@Total_Chaos wrote:

I note that you mention that you tried ports 465 and 587. If you were using port 465 that would be insecure email, whilst port 587 is for secure (STARTTLS) mail. To the best of my knowledge port 587 on PN won't accept insecure mail so unless you changed your settings then that wouldn't work, assuming that you normally use port 465.

Port 465 is deprecated, but is often used for ENCRYPTED email submission, using TLS/SSL. This port is NEVER used without encryption.

Port 587 is the RFC recommended port for email message submission either encrypted or not encrypted (insecure?) - where encryption is required, it should be set to STARTTLS.

In passing some set-ups suggest the use of port 25, which more correctly is the port for MX-to-MX communication for email message relay or delivery.

Re: SMTP gateway issue

red3 — Wed, 12 Oct 2022 06:56:58 GMT

For me REDS

Plusnet Broadband

Verified: Webmail both Send and Receive: verified working

Via Client:Outlook 2019

Was working fine until yesterday.

Incoming mail: iPOP still working

Outgoing mail: SMTP relay.plus.net 587

Auto

Outgoing SMTP requires Authentication - same as incoming

Error 0x800CCC0F The connection to the server was interrupted

Contact server administrator or internet service provider.

(Why don't Microsoft applications left you copy paste their fairly vague error message?)

Verified authentication failure via

TELENET relay.plus.net 587

Leads me to conclude => Something is rotten in state of PLUSNET's SMTP Server

Re: SMTP gateway issue

MisterW — Wed, 12 Oct 2022 07:57:18 GMT

Leads me to conclude => Something is rotten in state of PLUSNET's SMTP Server

Not sure how you come to that conclusion ?

Verified authentication failure via

TELENET relay.plus.net 587

That confirms that there's nothing wrong with the server.

The problem is Outlook or its configuration.

The forum is littered with posts about people having problems with Outlook.

Its also worth a google of 'outlook Error 0x800CCC0F'

Re: SMTP gateway issue

red3 — Wed, 12 Oct 2022 08:06:28 GMT

Hi Mister W

Thanks for the quick response but I don't think you are reading my post carefully enough.

Verified authentication failure via

TELENET relay.plus.net 587

It is NOT authenticating on the SMTP server.

Hence : Leads me to conclude => Something is rotten in state of PLUSNET's SMTP Server

This would rule out client

Now getting

C:\Users\Dell>telnet relay.plus.net 587

220 avasout-ptp-001 smtp relay.plus.net

Connection to host lost.

This is lower level of access and matches the Outlook Client error report.

Re: SMTP gateway issue

Total_Chaos — Wed, 12 Oct 2022 08:13:44 GMT

Just a quick one. The errors some are seeing you will get often when using a VPN. I use Surfshark as a VPN on both my Tablet and Phone. If I have it active then those errors you see you will get . Turn off you VPN then it works. On my Desktop I only use the VPN, I'm using Linux, I only use the VPN in the browser as an extension so I don't see them with Thunderbird.

Re: SMTP gateway issue

MisterW — Wed, 12 Oct 2022 08:21:59 GMT

@red3

Thanks for the quick response but I don't think you are reading my post carefully enough.

Oops, you're absolutely right, must go to specsavers. My excuse is that its early and I havent had my 2nd coffee yet.

So to confirm , when you try telnet , you get the initial response , then when you respond with the EHLO ... you get disconnected ?

Re: SMTP gateway issue

red3 — Wed, 12 Oct 2022 09:06:26 GMT

No prob. I'm on my 3rd coffee!

I think disconnecting is just a short time out before I get chance to do the EHLO.

Here's the response via TELNET

220 avasout-ptp-004 smtp relay.plus.net
EHLO relay.plus.net
250-avasout-ptp-004 hello [213.205.197.1], pleased to meet you
250-HELP
250-AUTH LOGIN PLAIN
250-SIZE 104857600
250-PIPELINING
250-8BITMIME
250-STARTTLS
250 OK
AUTH login
334 VXNlcm5hbWU6
[Base64 username]
334 UGFzc3dvcmQ6
[Base64 password]
535 ...authentication rejected

Re: SMTP gateway issue

MisterW — Wed, 12 Oct 2022 09:22:43 GMT

@red3 is there nothing after the '535 authentication rejected' ?

As @Townman suggested earlier, there's normally further details in the 535 rejection message

Re: SMTP gateway issue

red3 — Wed, 12 Oct 2022 09:43:41 GMT

Nope just: Connection to host lost."

C:\Users\Dell>telnet relay.plus.net 587
220 avasout-ptp-004 smtp relay.plus.net
EHLO relay.plus.net
250-avasout-ptp-004 hello [213.205.197.1], pleased to meet you
250-HELP
250-AUTH LOGIN PLAIN
250-SIZE 104857600
250-PIPELINING
250-8BITMIME
250-STARTTLS
250 OK
AUTH login
334 VXNlcm5hbWU6
[username Base64 encoded using Notepad++]
334 UGFzc3dvcmQ6
[password Base64 encoded using Notepad++]
535 ...authentication rejected

Connection to host lost.

C:\Users\Dell>

Re: SMTP gateway issue

MisterW — Wed, 12 Oct 2022 10:01:06 GMT

Ok, looking back through the thread, you say it was working yesterday.

Has your internet disconnected since then ? I'm thinking that you may have been allocated a different public IP which ghas a bad reputation. Even so, the telnet test ought be reporting the details, I dont understand why it isnt .

Re: SMTP gateway issue

red3 — Wed, 12 Oct 2022 10:23:04 GMT

I am remote so connecting over a tethered iphone on Plusnet mobile not from my home Plusnet broadband.

It has been reliable as a means of comms for many years and like I say working only yesterday.