Error "5.7.1 Reject for policy reason" when attempting to send email

[DavidM-1234]

I have had 2 emails that have failed to send in the last 2 days. Both showed the error "5.7.1 Reject for policy reason". The emails were sent to different individuals who I have previously successfully sent emails to/received emails from. I am using emClient as my email application but I had the same problem when trying to send the messages using WebMail. I have seen that there are lots of other instances of this error reported recently. Please can you suggest how it can be avoided or what is being done to fix it. Thanks for your help.

[Ady-TalkTalk]

If your mailbox has been sending spam it will have been blocked from sending mail. If you're able to send some please send me a private message with examples of those that you can send to and those you cannot so that I can look into it for you.

Ady

[DavidM-1234]

Hi, thanks for your reply. I am successfully receiving email and have been able to send some emails. However I have 6 emails today which were blocked with the 5.7.1 policy error. If I am able to receive email and to send some email is it still necessary to change my password (which will cause some other complications)? I assume that if my email is partly working then the problem is not my password - or is there some other reason why changing password is beneficial?

[Ady-TalkTalk]

Hi DavidM-1234, the first thing to do is to reset the password for a new one never used before with this mailbox. Once that's done please let me know if you're still unable to send mail.

Ady