Hosted Email IP reputation

OpenSRS may prevent senders from reaching our platform due to a poor reputation. Our team is welcome to review any requests in cases where reputation has improved.

Managing reputation

Email sent to our Hosted Email servers is subject to scanning. We check the payload of the message/body and all header information, including sender, destination, IP address, etc. Once a message is accepted, it may be flagged as unwanted by our system or the recipient. To avoid our system from flagging it automatically, senders will want to ensure the message itself doesn't appear spammy. While we don't have specific examples and cannot give tips on how to defeat our security, tips are available online to help lower spam scores.

OpenSRS has partnered with Validity to offer a Feedback Loop (FBL) tool for users sending many messages to users on our platform. The FBL forwards mail reported as spam originating from the associated IP addresses or domains to the provider. The feedback provided can ensure users don't continue the behaviour. This will help prevent email senders from being listed on our internal blocklists.
Note: Validity recommends using a dedicated email address for this purpose.

Determining listing status

We don't offer a dedicated tool to determine if IP addresses are on our block list. Email providers and senders see reject messages from our system advising of the failed delivery due to the IP address listed with us. The listing may be on our internal list or from our partners such as Abusix. In cases where Abusix has helped with the rejection, please review the instructions they provide on their IP address check tool. Once the IP is no longer listed with Abusix, we automatically remove it. 

Example messages

Messages with IPs on our internal blocklist contain error messages such as:

Messages blocked as a result of being listed in Abusix see errors such as:

Client host [] blocked using; Listed in Abusix Mail Intelligence, see

Requesting delisting

When OpenSRS has listed a sender in our internal blocklist, we prevent the email server from delivering email to users on the platform. Senders receive a bounce message letting them know that the IP address they are sending has been added and will want to send from another source or work with the sender to improve their reputation. It is the responsibility of the email provider to ensure their reputation maintains good standing with the internet community, 

Once reputation is improved, email providers may contact the OpenSRS support team to request the delisting. We verify the current standing and submit the immediate delisting request once a positive reputation is confirmed.

Back to top

Checking if IP is blocked

To check if your IP address is blocked by a 3rd party, you can use the MxToolbox blocklist checker. After entering your IP, if you see a green circle with OK, your IP is not blocked. If you see a red X, a real-time black lister has blocked your IP.



Back to top

Was this article helpful? If not please submit a request here

How helpful was this article?