Unable to send emails to Hotmail email addresses

[Frontera2]

Hi,

Whenever I try and send an email to a Hotmail address, I get the following error: 

"Your message to [name]@hotmail.co.uk has been blocked, see technical details below for more information"

At the bottom of the bounce back email it says:

550 5.7.509 Access denied, sending domain BTINTERNET.COM does not pass DMARC verification and has a DMARC policy of reject. 

Any ideas how this can be resolved? 

[licquorice]

I can send fine so it is possibly just one server that is misconfigured.

Check what your IP address is ( you can just go to https://whatismyipaddress.com/ to find out), disconnect your hub from line for about half an hour to trigger a different IP address. Check that it has changed, and try sending again.