Delivery failure 552 when replying to an email....

[#1]

Hi All

I did a search about this and I was getting similar undeliverable responses to this I found on another thread here.

SMTP error from remote mail server after end of data:
host relay.plus.net [212.159.9.107]: 552 z4jzefzg2sD7bz4k0eAR2M 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.

By a process of elimination I found that that by removing a clickable hyperlink of the senders email in my reply and making it plain text my reply to them went through AOK.

It is a small business I am in comms with and the signature includes clickable links to two other related businesses/websites they run.  The one with the issue is not the one in the email address.

So it appears that for whatever reason the PN outgoing servers are filtering but I cannot work out what it is about that URL that is the issue.  FWIW I was in comms with them earlier in this year and there was no issue with the delivery at that time!

TIA for any insight that I can tell them as to why that URL is an issue.  More than happy to PM a CSC the URL in question

[#2]

Sight of the URL (post it here) would be helpful.  There have been a number of false positives recently.

[#3]

Here is the URL

https://yoursourcetoday.com/

[#4]

Can confirm that URL within in an email gets bounced from Plusnet but not from 1and1 (cc arrived without issue.)

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its recipients. This is a permanent error. The following address(es)
failed:

postmaster@xxxxxxxx.plus.com:
SMTP error from remote server for TEXT command, host: mx.avasin.plus.net (212.159.8.200) reason: 552 Spam Message Rejected

[#5]

I have just re-replied leaving the above hyperlink 'live' i.e. not changed to plain text

I get this text in a System Administrator response email within seconds of sending it:- 

Your message did not reach some or all of the intended recipients.

      Subject:    RE: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

      Sent: 08/04/2018 11:11 PM

The following recipient(s) cannot be reached:

      'Xxxxxxxx Xxxxxxxx' on 08/04/2018 11:11 PM

            552 5IW8fnsTkUVt65IW9fWC7O 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.

I have X'ed out the personal info.

Hope that helps

As I say above URL shown is not part of the email return address but hyperlinked text in the signature of the sender I am replying to.

PS Sorry if I caused any confusion with my OP because I copied the error message from the other thread ~ I had deleted the previous sys admin responses