Hello,

I am trying to write to one of my clients, and I have the same problem always:

INVALID_ADDRESS, ERROR_CODE :550, ERROR_CODE :"JunkMail rejected - sender-of-o53.zoho.com [135.84.80.218]:21785 is in an
			RBL: SORBS - Currently Sending Spam See:
			http://www.sorbs.net/lookup.shtml?135.84.80.218"

The error only occurs with this client. I supossed that SORBS added the Zoho server IP in a spam list.

¿Can you help me with that, please?
Thank you.