• All Community
    • All Community
    • Forums
    • Ideas
    • Blogs

Not what you are looking for? Ask the experts!


Norton blocking outgoing email - email error 421 4.7.0

When trying to reply to an email in Windows Live Mail, Norton blocked the outgoing email with error message: "421 4.7.0 relay02.cambriumhosting.nl Error: to many errors"

Although in Windows Live Mail the email moved to the "Sent Items" folder, after checking it was 100% clear that it not reached the receiver. Then I disabled the email protection in Norton, and the email reached the receiver without a problem.

To be clear: there were NO ATTACHTMENTS in this email. Just plain text, nothing else.

This is not the first time Norton Security blocks my outgoing email. Few weeks ago I sent an email with a lot of Bcc's (also just plain text and no attachments). That too was blocked by Norton (email error 554 5.7.1 with the message "Recipient address rejected: Too many mails sent from your host within the last 10 minutes"). And that also could only be circumvented by disabling the email protection in Norton.

Today my Norton updated from version to But this issue stills exists.

Any suggestions?

File Attachment: 
Labels: Email Scan


Accepted Solution
Kudos3 Stats

Re: Norton blocking outgoing email - email error 421 4.7.0

421 errors can be solved through disabling outgoing email scanning, which is a non-essential feature that does nothing towards protecting your computer.


The 554 error was almost certainly returned by your email service provider's server and was not caused by Norton.  "Too many mails sent from your host within the last 10 minutes" is an indication that the large number of Bcc's likely ran afoul of your provider's spam filtering.


Re: Norton blocking outgoing email - email error 421 4.7.0

Thx for your response. Disabling the scanning of outgoing email by Norton is the pinpoint solution I was looking for.

Regarding the 554 error my line of thought was initially the same as yours. But three things make me doubt.

1. According to my ISP their mail server has a limit of 200 for outgoing emails. In my case it was an email with 1 for-all-to-see email address accompanied with 24 Bcc's. So, well below that.

2. In other instances when the mail server of my ISP had a problem with sending or receiving emails, it has always been my email client (Windows Live Mail, Outlook Express, etc) that informed me about the problem and relaying the error message. And that seems logical, because it is the email client that needs to communicate with the mail server in order to send and receive emails. But here it was only Norton that gave me the 554 error message.

3. One of the 24 Bcc's (later) turned out to be an email address that didn't exist. You always get those returned with the message that it was undeliverable. After my first attempt - when Norton gave the 554 error - I did not get it returned. After my second attempt (and having disabled the email protection in Norton) it did came back with the undeliverable message. That means it was indeed Norton who blocked it.

This makes me think that the 554 error is also caused by Norton. And if so, it can be solved the same way as with the 421 error.

It would be even bettter if Norton adds an option specifically for (the number of) Bcc's which will trigger a blockade.

This thread is closed from further comment. Please visit the forum to start a new thread.