SORBS Blacklist Help

I have a VPS with 123 reg, recently the emails I send aren't being received and have noticed are being blocked by Gmail due to spam - After googling i did a test on MX Toolbox which lists the below error:

LISTED SORBS SPAM

i contacted VPS support who provided instructions but i simply dont have the time to go through, need someone who knows what they're doing to quickly solve.