Plusnet emails refusing to send.

[#1]

@Annasdad 

I think your follow-up post must have sneaked in whilst I was doing my response (a lot of research whilst drafting it).  You and @sjpbarker now have the following in common...

• Force9
• Norton AV
• Certificate processing issues
• Win10

The diagnostics test all connections - it is easier than explaining!

• Inbound IMAP & POP3
• Outbound SMTP
• That covers users wanting to operate
  • POP3 & SMTP
  • IMAP & SMTP

We need to (at least) get to the point of the diagnostic running clean.  Can you please attempt to run the diagnostics as is with Norton on Pause and can you also try these variants

curl.exe -v imap://imap.force9.net -u you@youraccount.force9.co.uk
curl.exe -v pop3://mail.force9.net -u you@youraccount.force9.co.uk
curl.exe -v smtp://relay.force9.net:587 -u you@youraccount.force9.co.uk

The above commands will not use encryption.  If either of these are successful, that will point towards a certificate issue arising for some as yet unidentified reason.

Though not ideal, you will then have the option of sending without encryption.

In passing, I suspect that this error condition would simply present as a password error in an email client.

[#2]

It might be worth adding that on my iPad (without Norton) I have the same SMTP 550 error about being "blacklisted" when using Webmail to send an email using the Safari browser. When I use the Mail app I get the error "The sender address was invalid".

On my Android phone I just get "Failed" in red letters which is not very helpful.

Thanks for people's attempts to resolve this problem.

[#3]

Original diagnostics fail the same with Norton disabled.

Here are the results from the new diagnostics with Norton disabled

PS C:\Users\Dave> curl.exe -v imap://imap.force9.net -u <redacted>@<redacted>.force9.co.uk
Enter host password for user <redacted>@<redacted>.force9.co.uk':
* Host imap.force9.net:143 was resolved.
* IPv6: (none)
* IPv4: 91.204.208.196
* Trying 91.204.208.196:143...
* Connected to imap.force9.net (91.204.208.196) port 143
< * OK IMAP4 ready
> A001 CAPABILITY
< * CAPABILITY IMAP4 IMAP4rev1 UIDPLUS AUTH=PLAIN STARTTLS
< A001 OK completed
> A002 AUTHENTICATE PLAIN
< +
> <redacted>
< A002 NO Login failed.
* closing connection #0
curl: (67) Login denied
PS C:\Users\Dave> curl.exe -v pop3://mail.force9.net -u <redacted>@<redacted>.force9.co.uk
Enter host password for user '<redacted>@<redacted>.force9.co.uk':
* Host mail.force9.net:110 was resolved.
* IPv6: (none)
* IPv4: 91.204.208.196
* Trying 91.204.208.196:110...
* Connected to mail.force9.net (91.204.208.196) port 110
< +OK POP3 ready <684790294.1758792915@mail.enmail.co>
> CAPA
< +OK Capability list follows
< TOP
< USER
< UIDL
< SASL PLAIN LOGIN
< STLS
< .
> AUTH PLAIN
< +
> <redacted>
< -ERR Login failed.
* closing connection #0
curl: (67) Login denied
PS C:\Users\Dave> curl.exe -v smtp://relay.force9.net:587 -u <redacted>@<redacted>.force9.co.uk
Enter host password for user '<redacted>@<redacted>.force9.co.uk':
* Host relay.force9.net:587 was resolved.
* IPv6: (none)
* IPv4: 91.204.208.196
* Trying 91.204.208.196:587...
* Connected to relay.force9.net (91.204.208.196) port 587
< 220 mail.enmail.co ESMTP ready
> EHLO HomePC
< 250-mail.enmail.co
< 250-AUTH PLAIN LOGIN
< 250 STARTTLS
> AUTH PLAIN
< 334
> <redacted>
< 235 2.0.0 OK
> HELP
< 214-This is smtp ESMTP service help
214-This is smtp ESMTP service help
< 214-To contact postmaster send email to postmaster@plus.com.
214-To contact postmaster send email to postmaster@plus.com.
< 214-For local information send email to Postmaster at your site.
214-For local information send email to Postmaster at your site.
< 214 end of HELP info
214 end of HELP info
* Connection #0 to host relay.force9.net left intact
PS C:\Users\Dave>

Moderator's note:
Personal information removed from a public forum (to an area that staff can see).

[#4]

That seems conclusive - for some undefined reason your environment is not processing the security certificates correctly.

You might consider NOT using encryption on the SMTP server.

[#5]

I can see how to disable encryption using, for example, Thunderbird but how to do this using Webmail? When I did disable encryption on Thunderbird (with Norton off) the problem is still there.

[#6]

@sjpbarker 

Something seriously weird is going on.  My reply was expressly to @Annasdad whose test of the non-encrypted diagnostics did not encounter the certificate failure.

You are correct, anything done on the client or taking this approach is going to fix the webmail interface issues.  My suggestion is not a fix, but was intended to be a mitigation so that users might be be able to send mail whilst the issue is investigated.

@LexLex2020 / @plusnettony - is this on one of the lists please?

[#7]

I have checked all my outlook settings (compared to what I can find on the internet) and am not explicitly asking for encryption as far as I can tell but will accept that I may have missed something and I know that I'm repeating myslef but I have not altered anything.

I have just successfully sent an email - at least I didn't get an error when sending and am waiting to here from the recipient if they've received it- from another email address on the same account i.e. l**@lye29.force9.co.uk. I've checked all the settings on that email adress and compared them to my default account - dave@lye29.force9.co.uk and they are the same. So very confused.

Can I go back to where this al started - someone spoofing my email address. Do you hold a list in your mail servers of blacklisted addresses? I have just used MxToolBox and found that my email is blacklisted on Spamhaus ZEN. I'll see how to get it removed but do you use that list - or one from any where else to check if the address is blacklisted?

[#8]

Hi Dave,

Thank you - this is all really useful stuff.

Your last post points to potentially several issues

• the certificate issue
• email address (?) blacklisting
• your email address / platform is being abused

The certificate issue certainly seems to be inhibiting successful logon using the diagnostics when using encryption, given the multitude of issues, one cannot be certain if the email application is unable to log onto the server, or simply cannot send when having done so.

The report that everything works fine from one of the other mailboxes on the account suggests a mailbox / address specific issue, however that seems odd, based on the fact that your DOMAIN (not the email address) is black listed.  The details of that listing are...

Inclusion in the Spamhaus-ZEN Blacklist results from sub-listings in one or more the following Blacklists:

• CBL - You have contracted a virus or malware that is operating a botnet, either on your email server on a workstation behind the NAT - Continual delisting requests without eliminating the virus will result in permanent blacklisting
• XBL - (Spamhaus Exploits Block List) is a real-time database of IP addresses of hijacked PCs infected by illegal 3rd-party exploits, including open proxies
• PBL - Spamhaus PBL is a DNSBL database of end-user IP address ranges that should not be delivering unauthenticated SMTP email to any Internet mail server except those provided for specifically by an ISP for that customer's use

I recommend that you run a deep AV scan, ideally using a clean boot product and NOT Norton, for if Norton has not alerted you to anything, then there might indeed be nothing there ... or there is something Norton is not detecting.  Are you also running Windows Defender?

Have you had any 'strange' non-delivery reports?

Server connection without encryption requires the inbound port numbers to be changed...

• IMAP from 993 to 143
• POP3 from 995 to 110

All servers then need encryption setting to NONE - not ideal but it could help pin-point the source of the failures.

[#9]

I can's help thinking that this problem https://community.plus.net/t5/Email/Bouncing-emails/td-p/2021046

as yet unresolved is a similar or identical issue?

[#10]

Non delivery reports

     Yes had about 800 last week for mails that were not sent by me ( my PC was switched off when the emails were sent) but using my address so goodness knows how many emails were actually sent and if that had a virus on them.

No don't use windows defender. My POP3 port number has been 110 throughout. What should the relay port number be?

All the outlook server settings for encryption  that I can find (and checked by doing an online search) have not been set during all this so am confused what is causing the system to think the mail is encrypted.

I have run a deep Norton virus scan, Malwarebytes and spybot as soon as I receievd all the undelivered reports. Nothing found. I will look to get another virus checker.

So just to recap, the only changes my end were I changed my passwords after the non delivered messages mentioned above and I changed my BT openreach moem and Netgear router to a Plusnet Hub 2 (forgot to mention that before - sorry). Could this change becausing the problem? Is it worth reverting to the BT /Netgear configuration?

Dave

[#11]

Hi Dave,

No the routers do not have a bearing one this ... but helpful that you are considering all possibilities.

A deep scan is a wise move.

[#12]

@Townman 

Yes they have been, they also have a case open with advocates. They should be updating them directly.

[#13]

Just run a full virus scan from another supplier and no viruses found

[#14]

Things have become clearer - the abuse of your email address might not be sourced on your machine.  Matters are under investigation.

[#15]

I have just set up an SMTP2GO account and used their servers to successfully send an email using my free-online email address. This worked from Thunderbird and on Android.