From Newsgroup: uk.telecom.broadband

My mother is having problems with some mail not being delivered to
certain recipients. She uses Outlook (the Windows app, not the
outlook.com email domain) and email is getting to most recipients
without a problem.

If a message is sent to two recipients (either "to" or "cc" or "bcc")
and it arrives at one of those recipients, where is the problem likely
to lie? I presume a single copy is sent by SMTP to the server and the
SMTP server then "forks" it and sends copies to the various recipients.

The ISP (and therefore the owner of the SMTP server) is Plusnet.

I am also with Plusnet and I can successfully send (from Thunderbird) to
the recipients who don't receive from my mother.

It's all come to light because financial application forms have not been received, when sent to two different domains which belong to the same financial organisation. Without any "failed to deliver" error message,
there is an expectation that the emails have been safely delivered when
the correct address has been used (I copied and pasted the exact address
when I successfully sent, to avoid any retyping differences)
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.telecom.broadband

On 05/08/2025 17:28, NY wrote:

My mother is having problems with some mail not being delivered to
certain recipients. She uses Outlook (the Windows app, not the
outlook.com email domain) and email is getting to most recipients
without a problem.

If a message is sent to two recipients (either "to" or "cc" or "bcc")
and it arrives at one of those recipients, where is the problem likely
to lie? I presume a single copy is sent by SMTP to the server and the
SMTP server then "forks" it and sends copies to the various recipients.

The ISP (and therefore the owner of the SMTP server) is Plusnet.

I am also with Plusnet and I can successfully send (from Thunderbird) to
the recipients who don't receive from my mother.

It's all come to light because financial application forms have not been received, when sent to two different domains which belong to the same financial organisation. Without any "failed to deliver" error message,
there is an expectation that the emails have been safely delivered when
the correct address has been used (I copied and pasted the exact address when I successfully sent, to avoid any retyping differences)

This is serious but which email service is your mother using? PlusNet
are only the owner of the SMTP server if your mother is using PlusNet's
own email regardless of who is the ISP. I'm with PlusNet but I use a
variety of SMTP servers, none of which belongs to PlusNet.

If she is using PlusNet's own email service I suggest putting the
question on the PlusNet User Forum https://community.plus.net as that
can attract attention from technical people working for the company.
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.telecom.broadband

On 05/08/2025 17:28, NY wrote:

My mother is having problems with some mail not being delivered to
certain recipients. She uses Outlook (the Windows app, not the
outlook.com email domain) and email is getting to most recipients
without a problem.

If a message is sent to two recipients (either "to" or "cc" or "bcc")
and it arrives at one of those recipients, where is the problem likely
to lie? I presume a single copy is sent by SMTP to the server and the
SMTP server then "forks" it and sends copies to the various recipients.

The ISP (and therefore the owner of the SMTP server) is Plusnet.

I am also with Plusnet and I can successfully send (from Thunderbird) to
the recipients who don't receive from my mother.

It's all come to light because financial application forms have not been received, when sent to two different domains which belong to the same financial organisation. Without any "failed to deliver" error message,
there is an expectation that the emails have been safely delivered when
the correct address has been used (I copied and pasted the exact address when I successfully sent, to avoid any retyping differences)

Possibly her email address/domain is blacklisted somewhere and yours isn't?
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.telecom.broadband

On 05/08/2025 17:28, NY wrote:

My mother is having problems with some mail not being delivered to
certain recipients. She uses Outlook (the Windows app, not the
outlook.com email domain) and email is getting to most recipients
without a problem.

If a message is sent to two recipients (either "to" or "cc" or "bcc")
and it arrives at one of those recipients, where is the problem likely
to lie? I presume a single copy is sent by SMTP to the server and the
SMTP server then "forks" it and sends copies to the various recipients.

The ISP (and therefore the owner of the SMTP server) is Plusnet.

I am also with Plusnet and I can successfully send (from Thunderbird) to
the recipients who don't receive from my mother.

It's all come to light because financial application forms have not been received, when sent to two different domains which belong to the same financial organisation. Without any "failed to deliver" error message,
there is an expectation that the emails have been safely delivered when
the correct address has been used (I copied and pasted the exact address when I successfully sent, to avoid any retyping differences)

Very odd. Some of the emails I send from my PlusNet address (using
Outlook 2007) fail to arrive - but I invariably get 'failure to deliver' messages. This happens most frequently when the recipient has a Hotmail address. I am assuming that Hotmail sometimes decides that all PlusNet
emails are bad, and rejects them.

If I resend the failed emails to the Hotmail recipients, but using an
email account which doesn't use the PlusNet server (still using Outlook
2007), they arrive ok.

It will be interesting to see what happens when PlusNet migrates its
email service to Greenby!

I'm slowly changing all my PlusNet email addresses to ones based on my
own domain, both to avoid charges from Greenby once the free period ends
and to become independent of PlusNet, making it easier to change ISPs.
--
Cheers,
Roger
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.telecom.broadband

BrightonRock <harrymandispose-news@yahoo.com> wrote:

This is serious but which email service is your mother using? PlusNet
are only the owner of the SMTP server if your mother is using PlusNet's
own email regardless of who is the ISP. I'm with PlusNet but I use a
variety of SMTP servers, none of which belongs to PlusNet.

In other words, nowadays, you have to use the SMTP server that matches the email address you're sending *from*. So if you're sending from something@...plus.net you have to use Plusnet's SMTP server. If you're using
a different email address, send from the SMTP server operated by the people
who provide you with that email address.

If you have multiple email accounts set up in Outlook, set up an SMTP server per account - don't let them all send via a 'default' SMTP server (this was previously how to do things, but no more). That likely also means every
SMTP server needs a username/password login, rather than just using the PN server all the time you're on your home PC.

If you don't do that, you'll fail antispam checks and many big email
providers (Google, Microsoft) won't deliver your mail or will drop it into spam.

(if you have control over the domain's DNS or the outgoing server there are other things you can do, but if it's a big company like Plusnet you may not have that control)

Theo
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.telecom.broadband

Roger Mills <mills37.fslife@gmail.com> wrote:

On 05/08/2025 17:28, NY wrote:

It's all come to light because financial application forms have not been received, when sent to two different domains which belong to the same financial organisation. Without any "failed to deliver" error message, there is an expectation that the emails have been safely delivered when the correct address has been used (I copied and pasted the exact address when I successfully sent, to avoid any retyping differences)

Very odd. Some of the emails I send from my PlusNet address (using
Outlook 2007) fail to arrive - but I invariably get 'failure to deliver' messages. This happens most frequently when the recipient has a Hotmail address. I am assuming that Hotmail sometimes decides that all PlusNet emails are bad, and rejects them.

I would guess that emails that don't send failed delivery messages are being dropped into a spam box internal to the organisation. Maybe they have
policy that emails with spam score > N are automatically deleted or put into
a spam folder that is hidden from their users. Particularly if they use Outlook/Exchange, it may have been bridged from SMTP into Exchange-land and
as far as the SMTP transaction was concerned it was successful.

I've had this problem with organisations that use 'ticketing' systems - if Exchange thinks your message is spam, it never reaches the ticketing system
and so it never generates a post to the ticket so the users who are
subscribed don't get any notification about it.

Theo
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.telecom.broadband

On 05/08/2025 18:09, BrightonRock wrote:

On 05/08/2025 17:28, NY wrote:

My mother is having problems with some mail not being delivered to
certain recipients. She uses Outlook (the Windows app, not the
outlook.com email domain) and email is getting to most recipients
without a problem.

If a message is sent to two recipients (either "to" or "cc" or "bcc")
and it arrives at one of those recipients, where is the problem likely
to lie? I presume a single copy is sent by SMTP to the server and the
SMTP server then "forks" it and sends copies to the various recipients.

The ISP (and therefore the owner of the SMTP server) is Plusnet.

I am also with Plusnet and I can successfully send (from Thunderbird)
to the recipients who don't receive from my mother.

It's all come to light because financial application forms have not
been received, when sent to two different domains which belong to the
same financial organisation. Without any "failed to deliver" error
message, there is an expectation that the emails have been safely
delivered when the correct address has been used (I copied and pasted
the exact address when I successfully sent, to avoid any retyping
differences)

This is serious but which email service is your mother using? PlusNet
are only the owner of the SMTP server if your mother is using PlusNet's
own email regardless of who is the ISP. I'm with PlusNet but I use a
variety of SMTP servers, none of which belongs to PlusNet.

If she is using PlusNet's own email service I suggest putting the
question on the PlusNet User Forum https://community.plus.net as that
can attract attention from technical people working for the company.

She's using Plusnet as her ISP and Outlook is configured to use
Plusnet's SMTP server relay.plus.net to send.

I'm not yet sure whether it's *all* emails to given addresses which are silently failing to be delivered, or whether any of them are getting
through. I'd like to test it - eg do all email clients that use
relay.plus.net fail (eg her tablet and her mobile phone in addition to
her Win 10 PC); does it also affect emails sent from webmail.plus.net.
But's difficult to test when it's someone's work email address that you
are determining received / not-received.

Do SMTP servers generally accept emails with a From address that doesn't
match their own domain (eg sending an email from/reply-to a *.plus.com
email address via Gmail's SMTP server? Do they allow it if your mail
client provides a valid username/password as opposed to logging in anonymously? PN's server is quite happy to send email with no logon -
but only if oyu are connected to Plusnet, so that's no use for a
phone/tablet that will often be connected to a mobile network or a
friend's broadband. I have configured all my mail clients to log on with
the same username/password as is used for reading POP mail.

I'll go onto the PN forum and see if anyone can shed light on what is happening. The failing-with-no-error-message is more baffling than the
fact that sending from a blacklisted address/domain might get blocked
along the way.
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.telecom.broadband

On 05/08/2025 22:08, Theo wrote:

BrightonRock <harrymandispose-news@yahoo.com> wrote:

This is serious but which email service is your mother using? PlusNet
are only the owner of the SMTP server if your mother is using PlusNet's
own email regardless of who is the ISP. I'm with PlusNet but I use a
variety of SMTP servers, none of which belongs to PlusNet.

In other words, nowadays, you have to use the SMTP server that matches the email address you're sending *from*. So if you're sending from something@...plus.net you have to use Plusnet's SMTP server. If you're using a different email address, send from the SMTP server operated by the people who provide you with that email address.

If you have multiple email accounts set up in Outlook, set up an SMTP server per account - don't let them all send via a 'default' SMTP server (this was previously how to do things, but no more). That likely also means every
SMTP server needs a username/password login, rather than just using the PN server all the time you're on your home PC.

Yes, I've got three different types of email account on my
PCs/tablet/phone: some are Plusnet, one is Gmail and some are a domain
that we rent with email and web hosting by GoDaddy. I use the
appropriate SMTP server for each account.

Her email config hasn't changed for a long time. It's strange that we're
only now seeing a problem. It will be using relay.force9.net (her
address ends force9.co.uk rather than plus.com). If it was me, I'd set
up a Gmail account for sending in situations where sending from PN was
known to fail, but that requires careful juggling in the mail client to
make sure you send from a different address/account from the default
one. So I'm acting as piggy in the middle at the moment.
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.telecom.broadband

On 05/08/2025 17:28, NY wrote:

My mother is having problems with some mail not being delivered to
certain recipients. She uses Outlook (the Windows app, not the
outlook.com email domain) and email is getting to most recipients
without a problem.

If a message is sent to two recipients (either "to" or "cc" or "bcc")
and it arrives at one of those recipients, where is the problem likely
to lie? I presume a single copy is sent by SMTP to the server and the
SMTP server then "forks" it and sends copies to the various recipients.

The ISP (and therefore the owner of the SMTP server) is Plusnet.

I am also with Plusnet and I can successfully send (from Thunderbird) to
the recipients who don't receive from my mother.

It's all come to light because financial application forms have not been received, when sent to two different domains which belong to the same financial organisation. Without any "failed to deliver" error message,
there is an expectation that the emails have been safely delivered when
the correct address has been used (I copied and pasted the exact address when I successfully sent, to avoid any retyping differences)

If any of the recipients have mail hosted with Google or Microsoft, then
there are some lengthy discussion threads over on the PN forum
concerning greylisting/non-delivery, e.g: -

https://community.plus.net/t5/Email/Problems-sending-PN-email-to-Gmail-addresses/m-p/2012122#M50361

https://community.plus.net/t5/Email/From-address-doesn-t-meet-the-authentication-requirements/td-p/2011107
--
Bob Pullen
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.telecom.broadband

On 07/08/2025 07:48, Bob Pullen wrote:

If any of the recipients have mail hosted with Google or Microsoft, then there are some lengthy discussion threads over on the PN forum
concerning greylisting/non-delivery, e.g: -

https://community.plus.net/t5/Email/Problems-sending-PN-email-to-Gmail- addresses/m-p/2012122#M50361

https://community.plus.net/t5/Email/From-address-doesn-t-meet-the- authentication-requirements/td-p/2011107

The addresses that have caused problems are @barclays.com and @barclayscorp.com ones. Is there anything in those which would cause
problems, Bob.

Would there be any differences between sending from an X@Y.force.co.uk
account (my Mum's which silently fails to send) versus an X@Y.plus.com
account (mine which works). It's just occurred to me that this is a differences, even if both are operated by Plusnet.
My config (in Thunderbird) is

server=relay.plus.net
port=587
conn sec=STARTTLS
authentication=normal password

Her config (in Outlook) is

server=relay.force9.net
port=25
encryption=none


In both cases, SMTP authentication is enabled (using the same username/password as for POP incoming mail).


I presume that irrespective of the To address, the comms between the
client and the server is the same, and it is only when going from PN's
SMTP server and the recipient's POP server that any filtering, white/blacklisting and virus checking takes place.

The fact that she can send to most addresses suggests that it is
*probably* not a problem with her mail client or its SMTP config.
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.telecom.broadband

NY wrote:

The addresses that have caused problems are @barclays.com and @barclayscorp.com ones.

They use ProofPoint hosting, who are likely to have similar restrictions
on whether to accept or block email to microsoft/google.
--- Synchronet 3.21a-Linux NewsLink 1.2