Blocked by Spamhaus RBL

Hi guys,

I have a new cpanel webhosting server I setup with currently just my own site's and now got one customer hosting with me.

The server is only about 1-2 weeks old and I have done all sorts of EXIM hardening like ratelimiting deferred/failed messages and setting sending limit to 100 per hour.

Now the problem I have is, this customer sent an email to around ~90 of his contacts, all same email just saying basically they have a new email address, I can see in my logs that these emails were going through perfectly fine, until he had about 5 bouncebacks as these old contacts must have moved providers etc.

Shortly after, the emails started getting blocked by Spamhaus as the IP is now on their CSS list, I ran a test at MXtoolbox and also see we are now on "Protected Sky" as well.

Not sure why we got on there so quickly, the server has barely sent any emails until this customer started doing this, all other emails have been sent by myself personally and none of which are spammy, just conversations to customers. And I'd say probably a maximum of 50 emails in the last week.

Is it because the IP is new, so now he sent out this mass mail, it's penalized us due to so many BS emails in such a short time?

If so, how can I prevent this happening again, and how do I get off these lists?

Maybe a better idea to get a third-party service to act as a SMTP smart host? any suggestions on this?

Thanks everyone

 

Thanks yes I checked mail queue and that's how I figured out my customer sent out the 100 odd emails to his contacts, after discussing with him , the contents of the email was simply "I got a new email address xxx@xxx.com please use this, thanks" and so I figure seen my server is new, and IP has not got any real reputation yet, this huge offload of same messages from one person would've tripped the blocklists, I just hope it gets removed soon.

Using a third party service would get rid of the block problem though wouldn't it? Do you have any ideas for a good service to use? Our volume would easily be under 1,000 emails a month atm.

 

No not at all, we refuse to allow bulk emailing on our service to try make this kind of thing not happen, I've even actually set pretty low limits for hourly sending rates.

I found a place called SMTP2GO which allows you to specify them as a SMTP smart host, all our email is now routing through there and working perfectly, so eventually our spamhaus block should also disappear, but now it's not really an issue

I also found that the SPF records were not correct for our server hostname (as it is a subdomain of our main domain, and was not taking SPF from our main domain). I assume this is why we got on the blacklist in the first place!