Cannot send any Plusnet emails

[#1]

This is my first ever post in the community after being with Plusnet for many years.

On Wednesday I discovered that I could receive but not send any emails in both my email client (Outlook Classic) and in Plusnet webmail.

The error (below) is the same as has been posted in this thread and has been reported and escalated by me yesterday on support ticket Question #251675420

I, as another user in this thread, send out a weekly bulk email to 60+ people as I’m secretary of a community. I’m wondering whether this, which I last did on Tuesday,  has triggered the blacklisting as I’ve also had various non deliverables at times when sending an email to a bulk address list during recent months owing to Microsoft changing their policies in Hotmail, Live etc

Error Message in Outlook Classic

Task User1@Username.plus.com sending reported error (0x800CCC78) cannot send the message verify the email address in your account properties the server responded 550 User1@Username.plus.com sender rejected (blacklisted by local policy)

Error message in Plusnet webmail

SMTP ERROR (550) failed to set sender

User1@Username.plus.com

(<User1@Username.plus.com> sender rejected (blacklisted by local policy)).

I don’t think it’s to do with the greenby transfer as my wife on User2@sameusername.plus.com,  a different mailbox in the same account, has no problems at the moment sending emails.

It seems that 2 users in this thread have had the problem resolved and it may involve multiple servers according to plusnettony.  Can I be contacted by either @Leanne_T or  @plusnettony to resolve this please

I have done a deep scan with AVG anti-virus free and no malware was found

I don’t want to wait 6+ weeks as Darren did for this to be resolved as you now seem to know the fix. Help please.

[#2]

PM me your username please and I'll take  look. 

[#3]

Scratch my last post - I've found it, and done it. You should be OK now.

[#4]

Plusnettony to the rescue once again

Many Thanks Tony for what you did to fix it.

I think we would all like to know what is causing this problem to occur and what you have to do to fix it.

What are the chances of a re-occurence?

[#5]

@AndyS1 

The issue arises from some abuse arising involving your username and / or email address.  That does not mean that such was sent by you / your devices (though that is a possibility), nor does it mean that they were sent through your account, but they could have been.

Spoofing a sending address is exceedingly simples.

To protect services, attributes associated with abusing the service (by whatever means) get quarantined (blocked by local policy).  There is a risk that you could experience this again.

Regularly changing passwords is deemed to be best practice.