Cloudflare has a blacklisted IP address for email deliverability


#1

We noticed that one of Cloudflare’s IP addresses associated with our domain is blacklisted by one of the DNS based email blacklists. Even if our domain is using good email practices, other domains using this Cloudflare IP might be getting marked as spam. I believe this can easily have a negative impact on our email deliverability.

So, I was wondering if we could prevent our app from using this particular IP address. Is this possible?

Blacklist check:
https://mxtoolbox.com/SuperTool.aspx?action=blacklist%3A104.31.74.88&run=toolpage

Domains associated with this IP address:
https://viewdns.info/reverseip/?host=104.31.74.88&t=1


#2

Is this causing a problem with email delivery?


#3

Cloudflare IP addresses associated with a customer’s account are never used to send email. They are only used to accept inbound http/s requests.

This RBL has added the entire Cloudflare ASN, so there are no Cloudflare IP addresses not covered by this. They have also added all of Digital Ocean and AWS. An RBL can add any set of IP addresses they want… RBL maintainers tend to be zealots that way. No sane person would use this RBL.


#4

To my limited knowledge about email deliverability, I thought that the domain reputation as well as IP (for http requests) of your actual site also plays a role. For example, with Gmail your page rank can actually affect your deliverability. I could be wrong in this regard, though.

Glad that this particular list “Suomispam Reputation” is not one that should be taken seriously. Thanks for the prompt response and it seems there’s nothing here to be concerned with.