Not a question, but rather some information that might be useful for others.   I use Microsoft Outlook for emails. Recently I started getting this error message when sending emails (I could receive OK): Message rejected as it appears to be spam.  After several phone calls to TPG it was finally worked out that this was being caused by my VPN (NordVPN).  A bit strange as I have been using both programs (Outlook and NordVPN) for many years without any problems. All the same, by pausing NordVPN, I was able to send emails again. Not wanting to have to pause NordVPN everytime that I wanted to send an email, I contacted NordVPN and they advised the following: Our servers are configured to block the outgoing SMTP port 25 on standalone email clients in order to discourage the customers from using our service for spamming purposes. Could you please use alternative ports 465 or 587 as an outgoing SMTP port Instead for your connection? You can check this tutorial to change a SMTP port on some of the most common email clients: https://my.bluehost.com/cgi/help/140 Also, you could try disabling the CyberSec option under the Settings tab on our application.   As my outgoing SMTP port was already set to 465 (not 25), I did not change any port settings. However I did disable the CyberSec option under the Settings tab on the NordVPN application.   Problem fixed! I can send emails again.   ... View more