mass of emails bouncing back however they delver from my gmail account? see error code: SMTP error from remote mail server after end of data: host outbound.jnb.host-h.net [220.127.116.11]: 550 High probability of spam
Check that you don’t have any spam type content in your emails, both body and subjects.
Do these rejected emails have signatures?
Thank you for your prompt feedback.
I have done so, my colleague seems to be able to send these emails however mine bounce?
I do indeed have a signature.
Sometimes a signature can be the cause. Try and send one of them again, but without a signature, and see if that works.