552 Spam Message Rejected

[#1]

Hi all,

I've just replied to someone that I have emailed previously with no issues. 

I am using relay.plus.net as my outgoing SMTP server so there are no proxies or separate mail servers running in between my email client and the internet (well there are, but I have bypassed them because I got this message.)

Yet I have this email:

The following recipient(s) cannot be reached:

      'Joe Bloggs' on 16/02/2017 11:00

            552 lNzY1u00408dvRf01NzZZC message rejected due to spam or virus. If you believe this is in error please login to your portal or contact your ISP support team.

Now this person works for a law firm and there is 100% no spam or virus content within the email (do people still get viruses on emails?! How very 90s/2000s!).

If I log onto my webmail portal that sits outside of the plus.net network, the email is sent without any problem. If I VPN out from my plus.net connection, and use a 3rd party mail server which I have access to, the email is sent with no problem.

So there must be an issue / rule / flag in cloudmark that is causing my email to be flagged erroneously as spam/virus.

Can you please have a look for me?

Thank you.

[#2]

That really is strange! I also have been having similar problems along with one or two others...

https://community.plus.net/t5/Email/RBL-Restriction-Blacklisted-by-Internal-Reputation-Service/td-p/...

https://community.plus.net/t5/Email/552-Spam-Message-Rejected/td-p/1414336

https://community.plus.net/t5/Email/Email-delivery-error/td-p/1411975

[#3]

Looks like Plusnet have a problem somewhere then!

Thanks for the reply!

[#4]

PM me the sender/recipient address and a copy of the email content and I'll look into it.

[#5]

Thanks bob - PM on the way.