Server Error 421 Can't Send Emails

[RobertsE]

Hi, please can you help, long time watcher, first time poster. So please be patient....
I recently found that I can't send emails from my Windows Live Mail application, I can receive OK but I get the following error message when sending:

Server Error: 421
Server Response: 421 csmtp5.tb.ukmail.iss.as9413.net cmsmtp Virgin Media has blocked your connecting IP xx.xx.xxx.xx Too many bad emails have been sent.

I have tried the usual things like updating the email settings to the latest ones (it is an .ntlworld email address), changing the password.

I scanned the computer for viruses and didn't find anything. I tried installing another email client, but that gets the same error.

I tried the virgin Media Customer Support line without any success. And I tried reporting it to the virginmedia netreport team, but I didn't get a response.

I can send emails fine through the web mail page, but I really want to use a PC based mail package.

Any suggestions, how I can get up and running again I have run out of ideas. And what could I have done to cause the problem in the first case.

Thanks in advance for any help.

[用心棒]

Can you open a Windows Command Shell, run the following command and post its output here?

curl smtps://smtp.virginmedia.com

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[Serena_C]

Hi @RobertsE

Welcome to our Community Help Forum 🙂

Thank you for making your first post regarding the issues you are experiencing when sending emails from Windows Live Mail. I'm sorry to hear you are having this problem.

If you are using Windows 10 can you open a command Window and enter the following line:

curl -v smtps://smtp.virginmedia.com/ -u username:password 2>&1 | findstr "235 VM"

Please do keep us posted on the result 🙂

Kind regards,

Serena

[RobertsE · Accepted solution]

Thank you for the responses.

I have tried entering 

curl smtps://smtp.virginmedia.com

But I get the error message 

curl: (35) schannel: next InitializeSecurityContext failed: Unknown error (0x80092012) - The revocation function was unable to check revocation for the certificate.

Am I doing something wrong??

[RobertsE]

Thanks Serena,

I have tried entering:

curl -v smtps://smtp.virginmedia.com/ -u username:password 2>&1 | findstr "235 VM" into command prompt on windows 10 with my password and username, but I don't get any response. Any ideas again what I have done wrong??

[用心棒]

You have run both command correctly and the issue highlighted is something the forum team will need to take forward.

---

@ModTeam, SMTP server's certificate's Certificate Revocation List (CRL) cannot be retrieved resulting in its validation failing. This issue has been raised a handful of times on the forum but tends to resolve itself in the period between now and before its investigation. The cohort nature of the issue does suggest it maybe a Content Delivery Network (CDN) issue.

cc: @ravenstar68

[ravenstar68]

@Serena_C 

The curl command wouldn't have actually told you anything different even without the certificate revocation error.

The first post contains all the information you need here:

Server Error: 421
Server Response: 421 csmtp5.tb.ukmail.iss.as9413.net cmsmtp Virgin Media has blocked your connecting IP xx.xx.xxx.xx Too many bad emails have been sent.

The user has already followed the advice that he's missed off the end here and gone to the Virgin netreport site, but the report hasn't been looked at.  Coulld you chase this up for them.

Tim

P.S I wish modern clients would go back to actually reporting the error message like Live mail.

[Gareth_L]

Hello RobertsE

Sorry this is happening to you 

I can look at this in a bit more detail and get the IP address unblacklisted 

I will need to send you a private message to pass security 
If you can check the purple envelope top right of your screen that would be great 
Regards     
Gareth_L