Plusnet emails refusing to send.

[#1]

That kind of sums things up very neatly.

The SMTP command was run with encryption (--ssl-reqd) and it failed.

The IMAP and POP3 connections WITHOUT encryption were successful.

So you might consider changing the server setting in your email client...

• POP3 - Port 110 encryption - none
• IMAP - Port 143 encryption - none
• SMPT - Port 587 encryption - none

Use the same user ID and password as per the above tests.

If that works, then we need to determine why the certificate verification steps fail in the cURL diagnostic.  I have seen references to issues with AV software, I think you have mentioned you use Norton?

See windows 11 curl: (35) schannel: next InitializeSecurityContext failed: CRYPT_E_NO_REVOCATION_CHECK (...

Also this - windows - All HTTPS connections outside of browser fail with "SSL certificate problem: unable to get...

Specifically: Using Norton Antivirus, I disabled the "Safe Web" feature. More specifically, I disabled the "HTTPS Scanning" option within the "Safe Web" feature and kept the other options enabled as I wished.

This is telling: I have switched to another antivirus software (with a different engine) and the curl command started working again.

I counsel caution here: it is difficult to know if all of the failures seen relate to the matter discussed in the PM - user ID format or password characters.  There are two paths for your here...

1. Affirm that the CURRENT email client details have the correct user ID and password - any doubt just user accountname as the userID
2. If the above still fails, switch the server connections to be un-encrypted - if that works, then we need to find the smoking gun

Not until you have done the above should one explore the Norton consideration, for now it is appropriate that it is considered as a potential source of issues.  There remains some possibility that the observed behaviour is nothing more that an interaction between just Norton and the cURL diagnostic, having no bearing on the email client failure.

The fact that you and at least one other around here has reported an identical symptom and they also use Norton raises valid grounds for considering that a recent update to Norton might be responsible.  But lets do the profiling first.

[#2]

@Townman 

Thanks for your continued work on this but I'm still confused.

 My ports are as reccommneded above 

I still have one rmail address working and one failing on the same account. They have identical outlook parameters.

So not sure where that leaves me.

Dave

[#3]

Dave,

Sone clearer details about the accounts and the diagnostic results.

@Pancho4 ’s results show that the diagnostic without encryption passes.  What happens for you?  If the diagnostics pass for you then the server connection without encryption is worth attempting.

If that fails for you then you need to share the detail.

At the moment there’s enough grounds to suspect the possibility that Norton is a contributor.

[#4]

@Townman 

Thanks for the reply and sorry if I'm being a bit slow on the uptake but I'm still confused. 

I have 2 email addresses on the same account operating from the same computer. The settings for both email addresses are identical. One can send emails and the other can't so I'm at bit of a loss to understand what Norton or encryption has to do with it.

 The ports are as recommended. I have have checked the properties of an email to be sent from both accounts and both say they are not encrypted.

The commands you suggest we should run are acting at the account level so I'm sure what they will achieve given that they I have a working email address on that account.

All this started after someone one spoofed the  failing email address. I got just shy of 800 non delivery reports to the failing address and as the outlook error message says the address is blacklisted it does seem to tie in - or am I just being too simplistic.

Once again, thanks for your efforts in trying to solve this and I'm sorry not understanding the responses.

Dave

[#5]

Hi Dave,

It helps to provide the precise detail rather "ports are as recommended" ... as its whose recommendation - some of the recommendations around here are flawed.  Reading back through your posts here to assemble the details shared...

• #63
  • Email client outlook (but version not specified)
  • Force9 mail address
  • error (0x800CCC78)
  • sender rejected (blacklisted by local policy)
• #68
  • Authentication - accountname -> from that one infers davesaccount or davesaccount+secondary.mailbox
  • Mailboxes impacted - default and secondary
• #69 diagnostic results -> unclear which email address (default or secondary) was used
  • IMAP - Failed - certificate processing error
  • POP3 - Failed - certificate processing error
  • SMTP not run
• #71 diagnostic results -> as above
  • SMTP  - Failed - certificate processing error
• #74
  • advises Norton AV is used with an inference that it does not change (so cannot be the problem) - but it does, it is updated all of the time, so could become a problem (if only for the diagnostics)
  • confirms the environment is win10
• #78 - on reflection that unfortunately makes two changes (not one) - uses the unencrypted diagnostics with Norton switched off
  • IMAP fails
  • POP3 falis
  • SMTP suggests success, but in the light of the above, I remain unconvinced
• #82 - setting check, not explicitly asking for encryption: if inbound use ports 993/995 then that implicitly calls for encryption; SMTP needs STARTTLS specifying
• #85 - that is the first clear statement of configuration - POP3 on port 110 - (which implies mail.plus.net and NONE to encryption)
• #100 - reports email sent OK on one address, but not another, with no reaffirmation of the error details - note that it is the domain name which is blacklisted, not the email address

There's a lot of inferred things, not stated explicitly, which leaves one guessing and needing to make presumptions, especially give the one address works, the other does not statements.

• Are the working and not working addresses on the SAME PC, using the same instance of Outlook?
• Which version of outlook - the proper paid for version or the pretend to be outlook free one?
• Which email address works / does not - the default address or a secondary?
• Are you connected to the Plusnet network or using another ISP's network?
• Do you get the failure immediately on attempting to send or after a short while?

[#6]

@Townman 

Sorry if I've not been clear

• Are the working and not working addresses on the SAME PC, using the same instance of Outlook?

          Yes

• Which version of outlook - the proper paid for version or the pretend to be outlook free one?
  • Version 2508 which I think is the proper version
• Which email address works / does not - the default address or a secondary?
  • Default fails secondary works
• Are you connected to the Plusnet network or using another ISP's network?
  • Connected to Plusnet
• Do you get the failure immediately on attempting to send or after a short while?
  • Immediately
• Port numbers
  • mail.force9.net 110
  • relay.force9.net 587

Hope this helps. Let me know if it doesn't

dave

[#7]

Hi Dave,

Thank you - that is all very helpful.  It summarises as follows...

• You have two mailboxes configured as POP3 clients in the same instance of Microsoft365 Outlook (which is one version old - I have Microsoft® Outlook® for Microsoft 365 MSO (Version 2509 Build 16.0.19231.20044) 64-bit)
  • default@youraccount.force9.com
  • secondary@youraccount.force9.com
• The sending device is connected on the Plusnet network
• secondary@ sends OK without issue and the emails are received by the addressee
• default@ encounters a blacklisted sending block error - can you please check / affirm the following...
  • the from / sending address is the same as the account address - that is send on behalf of is not being used
  • the authentication setting on the SMTP server is the same as the incoming server

For the avoidance of presumption - the default address configuration is still receiving emails?

My diagnostic issue at this point is that to the best of my knowledge black listing is applied at the domain level, so it is odd that one email address sends successfully whilst another does not due to blacklisting constraints.

Can you please check you domain's blacklisting status here - Email Blacklist Check - IP Blacklist Check - See if your server is blacklisted - check @you.force9.co.uk and @you.f9.co.uk

In the meantime, I will work on a different diagnostic test for you to try.

[#8]

Hi Townsman,

Following your recent helpful comments, I ran the diagnostics unencrypted using my primary email address and password, just to check the credentials - with the same outcome ie IMAP/POP OK and SMTP fail.

I then, following your recommended servers setting in your post, tried to ensure that my outlook settings were the same. This was problematical as the outlook setting routines appear to need an effective server connection to verify and save the changed values and this didn’t often happen. The outlook server repair routines never completed successfully, rejecting or timing out. I then did a repair on the outlook software, ran outlook in safety mode and then used outlook tools to modify the settings to see if that worked There were still some slight variations in the server data between what I could see in outlook directly and what outlook tools showed me however. Strange?

I fiddled around in outlook a bit more and lo and behold I was able to receive incoming mail to the PN main email address but, as expected, no sending. I then disabled the https check settings in Norton Safeweb to see, and tried again, successfully to receive incoming mail. So I have re-enabled the https setting in Safeweb and still can receive mail - so the Norton AV effect may not be the problem. 

However, that was yesterday and today when I try to receive mail on the primary account - no luck and I'm stumped.

However, I still think this problem overall comes from within Plusnet somewhere:-

• The outlook setting update routines seem vulnerable to updating - should I try another email client? BUT 
• We still have two iPads that were sending and receiving PN mailbox emails up to 2 weeks ago and getting sporadic receive on one, not the other and but no sending from either.

I will continue to play around and try and recreated the successful incoming mail conditions on outlook. Really grateful for any recommendations here?

Thanks for your patience  John

[#9]

Just as an addendum I have spotted that my domain XXXXX.f9.co.uk is blacklisted on Spamhaus ZEN - but my attached email id@domain.co.uk is not listed. This is using the MX Supertool. Is this real and/or is it a possible factor? 

[#10]

That can be real.

Blacklisting is by domain name - the native domain and your domain are not the same.  Such is why initial testing of the Microsoft and Gmail issues were so difficult - everything I do is sent from my hosted domain ... hence those issues were never encountered, until attempting to send from the native domain name.

[#11]

Interesting. Because of the current email problems I have been sending some replies from webmail which of show the native f9 domain as their origin - and there has been no evidence of any blacklisting of them. Could this blacklisting be a problem? Presumably therefore this is unrelated to all the other email problems being experienced?

cheers

[#12]

any idea how long this will last? i can still recieve mail, just not send any

[#13]

---

@Pancho4 wrote:

Just as an addendum I have spotted that my domain XXXXX.f9.co.uk is blacklisted on Spamhaus ZEN 

---

Which Black list ?  PBL?

Do you have a static IP address?

What happens if you remove authentication from the SMTP server - do you get a 4.3.2 internal server error when you attempt to send?

[#14]

Thanks for your reply. The blacklist tool says Spamhous Zen. I went on Spamhaus to find out more, when I tested my f9.co.uk domain there, it came out all clear.  So I think this is a red herring. 

Thanks 

[#15]

To summarise my position/problem

• Classic Outlook 365 (bona fide copy) worked perfectly on a Windows 11 PC using as main email account my primary email address (name@mydomain.co.uk). We have a PN fibre500 broadband connection and have been with PN/F9 for broadband and domain hosting/email for over 20 years.
• PC outlook worked until 20 or so days ago - then sending failed got messages"(0x800CCC78): 'Cannot send the message. Verify the email address in your account properties. The server responded: 550 <address@domain.co.uk> sender domain rejected (blacklisted by local policy)'"
• At the same time two ipads stopped sending emails from PN (name@mydomain.co.uk) addresses – suggesting a broader problem than just the Outlook mailbox
• Examination showed that the Outlook server settings were showing the plus.net server details (rather than Force9) and port settings of 995/25 +encryption – these were not the F9 recommended settings but this configuration had worked for years (obviously wrongly)
• The cURL email diagnostics were run – and showed after some false starts, amended server details, and some tweaking that
• The SMTP command was run with encryption (--ssl-reqd) and it failed.
• The IMAP and POP3 connections WITHOUT encryption were successful.
• The port settings recommended by Townsman were used (110/143/587)
• It seemed at this stage that there might be some improvement here. HOWEVER it has proved impossible so far for me to make the necessary changes to outlook – every time a change is requested to the server/port settings it fails either to complete or returns the error message “something went wrong and outlook couldn't save your account settings”
• I have tried seemingly everything to rectify this issue: quick repair of outlook 365, full repair of outlook, deep antivirus scan, operate outlook in safety mode, using the “outlook tools” utility and even registry editing. But none have enabled a full lasting correctional edit to the server settings, to return the necessary functionality. A couple of times I was able to receive some emails into the F9 name@mydomain.co.uk mailbox but only transiently.
• A google search seems to suggest that this outlook failure to save settings does seem to occur frequently - but that an appropriate registry edit corrects it. However, it seems to me that this failure to update the mailbox settings is because, for some reason, imperfect connection/fault/whatsoever, outlook is unable to connect properly to the F9 servers to verify any data corrections
• In the meantime our two ipads remain unable to send emails and one can receive and the other not.
• We should not forget that, throughout all this long conversation about defective receiving of emails, no one has yet apparently addressed the other, just as serious issue, of why emails will not send from the plusnet environment from a variety of devices and operating systems.
• I’m only surviving because the webmail interface is working OK!

In frustration !