topic Problems with sending email via Plusnet to Fasthosts Livemail SMTP server in Email

Problems with sending email via Plusnet to Fasthosts Livemail SMTP server

RCFlyer — Sat, 25 Dec 2021 22:35:28 GMT

For a couple of days now, we've had issues sending emails whilst connected via Plusnet. We have our own domain, hosted by FastHosts. The server is returning the following error:

An error occurred while sending mail. The mail server responded:
<xxxxxx@xxxxxxxxxxx.co.uk>: Recipient address rejected: Access denied.
Please check the message recipient "xxxxxx@xxxxxxxxxxxx.co.uk" and try again.

This happens via all PCs and mobile devices whilst connected via Plusnet. If I turn my phone's WiFi off, so that I'm connected via my mobile data, the problem goes away, so it does appear to indicate this is a Plusnet connected problem.

Please note - although this appears to be an email problem, it isn't! Please don't move to the emails section!!!

Re: Problems with sending email via Plusnet to Fasthosts Livemail SMTP server

dvorak — Sun, 26 Dec 2021 11:28:58 GMT

Moderators Note

This topic has been moved from Fibre to Email

Re: Problems with sending email via Plusnet to Fasthosts Livemail SMTP server

RCFlyer — Sun, 26 Dec 2021 23:43:14 GMT

Well I tried!

This isn't a Plusnet email issue, it's to do with my Plusnet broadband connection, hence my request not to move it to the email section.

Re: Problems with sending email via Plusnet to Fasthosts Livemail SMTP server

LaurenB — Mon, 27 Dec 2021 09:46:49 GMT

Hiya @RCFlyer, thanks for getting in touch. I am sorry for the delay in getting back to you and for the problems you are having with your emails sending.

Does this happen to all mail that you are trying to send, no matter the recipient?

Looking over the connection, the only thing that's really changed in the last few days is your IP address so might be worth turning your router off and leaving it off for about an hour if able to, to try get a different IP assigned and see if this makes a difference.

If the issue is continuing, if you can please send over a PM (to send a PM, click on my name and then to the right, there will be a grey button to 'send private message' and in the message please include a link to this thread) with the email headers and we can raise this to our Net Ops Team to look at further. If using Outlook, further help on obtaining headers can be found here: https://support.microsoft.com/en-us/office/view-internet-message-headers-in-outlook-cd039382-dc6e-4264-ac74-c048563d212c

Re: Problems with sending email via Plusnet to Fasthosts Livemail SMTP server

Townman — Mon, 27 Dec 2021 11:01:38 GMT

@RCFlyer wrote:

For a couple of days now, we've had issues sending emails whilst connected via Plusnet. We have our own domain, hosted by FastHosts. The server is returning the following error:

An error occurred while sending mail. The mail server responded:
<xxxxxx@xxxxxxxxxxx.co.uk>: Recipient address rejected: Access denied.
Please check the message recipient "xxxxxx@xxxxxxxxxxxx.co.uk" and try again.

For total clarity ... are you attempting to send via the Plusnet SMTP servers rather than FastHost's?

There is the possibility of your description being read this way ... some people use the SMTP server of their ISP rather than their email provider.

If you are using FashHost's SMTP server (as recommended here - Set up Email on your computer, phone or tablet (fasthosts.co.uk) ) then you need to ask this support question of FastHost.

My suspicion would be that FastHost is treating your IP address as not being a UK address, through their use of obsolete IP address geolocation data. As such there is nothing which Plusnet can do to assist here ... unless there is a genuine error on their geolocation data. Have a look here ... IP Address Lookup - Check Location of Your Public IP (iplocation.io) ... note any variability of the reported location. If the geolocation data looks totally wrong please report your A.B.0.0 IP address back here.

If you are not using Plusnet's SMTP servers then there is little point in sending over the email headers. What might be informative is to check the SMTP server connectivity in a manner which will disclose the precise error condition. If you get past this test (see the guide below), then its worth attempting a diagnostic send ... see Check an SMTP Connection W/ Manual Telnet Session: How-To Guide (sparkpost.com) and particularly for SmartHosts (which I believe uses Exchange) Use Telnet to test SMTP communication on Exchange servers | Microsoft Docs

Hopefully something above will give you a definitive error condition ... rather than just the consequences ... an inability to send the email...

Test SMTP authentication

In the guidance below, use YOUR SMTP server's address, not Plusnet's

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: Problems with sending email via Plusnet to Fasthosts Livemail SMTP server

RCFlyer — Mon, 27 Dec 2021 22:14:09 GMT

Townman, thanks for the guide.

I've attempted to login to my mail server (I am using smtp.livemail.co.uk) but it fails at the password step:

535 ...authentication rejected

There is no further error reported.

Re: Problems with sending email via Plusnet to Fasthosts Livemail SMTP server

Townman — Tue, 28 Dec 2021 08:41:11 GMT

That’s usually due to the user name / password being wrong. At this juncture, raising the query with FastHosts might shine more light on the issue.

Did you check the IP address geolocation data?

Re: Problems with sending email via Plusnet to Fasthosts Livemail SMTP server

RCFlyer — Tue, 28 Dec 2021 22:09:39 GMT

My username and password are correct; on my mobile phone with the WiFi off, I can send mail; as soon as I put my WiFi on, so that I'm using my Plusnet BB connection, it fails.

The various IP address geolocations were all in the UK, although they did vary in which part of the UK.

I have since reset my BB modem and router, as we had an outage in the early hours which caused a loss of connectivity (another issue we see regularly, but easily resolved).

Re: Problems with sending email via Plusnet to Fasthosts Livemail SMTP server

Townman — Tue, 28 Dec 2021 22:40:48 GMT

The fact that this appears to be associated with your broadband IP address points to some “discernment” (rightly or wrongly) by your hosting company. Have you raised the issue with them, asking why they are black balling that IP address?

Re: Problems with sending email via Plusnet to Fasthosts Livemail SMTP server

RCFlyer — Sat, 01 Jan 2022 01:29:29 GMT

I have raised a ticket with Fasthosts, they deny that they are blacklisting any IPs.

Re: Problems with sending email via Plusnet to Fasthosts Livemail SMTP server

Townman — Sat, 01 Jan 2022 09:57:31 GMT

If they believe they are not blacklisting then they need to inspect why there are issues with the PlusNET IP address. All sensible email providers profile email submission network addresses by one means or another.

Re: Problems with sending email via Plusnet to Fasthosts Livemail SMTP server

Townman — Sat, 01 Jan 2022 11:32:48 GMT

You can check to see if your IP address is black listed here - IP Address Blacklist Check - WhatIsMyIP.com® - if it is, then you need to flag that back here for Plusnet's attention.

Re: Problems with sending email via Plusnet to Fasthosts Livemail SMTP server

RCFlyer — Sat, 01 Jan 2022 21:10:27 GMT

No, the IP address isn't blacklisted with any of the lists.

I have raised a ticket with Fasthosts as well, but not much progress so far.

Re: Problems with sending email via Plusnet to Fasthosts Livemail SMTP server

RCFlyer — Sun, 02 Jan 2022 21:48:57 GMT

I received this response from Fasthosts Customer Support

'I would suggest to contact your ISP provider to check if they can assign/give you a different IP to connect, looks like it is now down to your ISP supplier and the IP address they have given to you. Were you able to send out emails before using the same ISP provider?.'

So they've basically thrown it back to Plusnet.

Re: Problems with sending email via Plusnet to Fasthosts Livemail SMTP server

Townman — Sun, 02 Jan 2022 22:09:58 GMT

If I received a response like that, I would be pushing back on them. I would be asking them to explain why they are blocking your IP address. Until the explain that with legitimate cause for concern, justifying a refusal to connect to the mail server, this is their problem to fix.

Just to clarify, you are using port 587?

Have you checked the reported IP address location? Use this service - https://iplocation.io/ - it checks numerous geolocation data providers … which starts to illuminate the issues surrounding presumptions on user location based on IP address.

Re: Problems with sending email via Plusnet to Fasthosts Livemail SMTP server

RCFlyer — Sun, 02 Jan 2022 22:09:41 GMT

I will do that.

I use port 465 for the SMTP server as that'ss what they specify.

Yes, as mentioned yesterday, all IP address resolves to UK locations.

Re: Problems with sending email via Plusnet to Fasthosts Livemail SMTP server

Townman — Sun, 02 Jan 2022 22:11:02 GMT

465 is deprecated (ought not to be used). Try 587 with STARTTLS.

Re: Problems with sending email via Plusnet to Fasthosts Livemail SMTP server

RCFlyer — Mon, 03 Jan 2022 02:26:46 GMT

When I queried why certain IP addresses might cause problems, I received this reply:

'There are certain SMTP protocols that are not allowed by your ISP. You can try changing your SMTP port from 465 to 25 without SSL and check if this works.'

This sounds like a 'brush off' response to me; why would I want to switch to an unencrypted SMTP connection?

Re: Problems with sending email via Plusnet to Fasthosts Livemail SMTP server

Townman — Mon, 03 Jan 2022 09:18:53 GMT

Exactly!! Not just a brush off but poorly informed.

Historically (and possibly still the case) some network managers (particularly businesses) totally blocked SMTP access to “off network” servers on port 25, whilst permitting on ports 465 and 587.

Following strict adherence to standards, email messages should not be submitted on port 25 - that is designated for MX to MX message relay. Port 465 used for message submission has been deprecated. That leaves 587 as the correct port for email client message submission.

You telnet diagnostic test makes very plain that Plusnet is not blocking access to your host’s SMTP service as suggested by the response above … it is THEIR server / network which is blocking your login. They need to investigate why.

Re: Problems with sending email via Plusnet to Fasthosts Livemail SMTP server

RCFlyer — Wed, 05 Jan 2022 22:46:26 GMT

They carried on insisting that I try Port 25 with no security; I gave in and tried it so they could follow their script, but it didn't work, of course.

Edit: I've just been checking my old PMs and noted that we had the same problem in March, but it fixed itself after a couple of days!