IP address on block list – What to do?
If your IP address is on a block list, it means that it has been identified as a source of spam or other unwanted content. This can cause emails sent from your server to be blocked by certain email providers, such as Gmail or Yahoo.
The error message may look something like this:
SMTP error 550: 5.7.1 Recipient not authorized, your IP has been found on a block list
Especially annoying: Outlook
Learn why Microsoft has blocked some IP address ranges and how we are working to improve email delivery quality.
Why can’t I send emails to Gmail or other email providers if my IP address is on a block list?
Email providers use block lists to filter unwanted emails and spam. If your IP address is on a block list, this can cause the emails sent from your server to be blocked by these providers. This can lead to important emails not being delivered and your communication being affected.
What can I do if my IP address is on a block list?
If your IP address is on a block list, you should contact our customer support. We can provide you with “clean” IP addresses that are not on block lists. This will ensure that your emails are delivered and your communication goes smoothly. Note, however, that in this case we need to know what kind of mail traffic you are sending. For private applications, we are guaranteed to always find a solution. For larger projects, such as transactional mails, we recommend other solutions.
Use DKIM & SPF
The use of DKIM and SPF can improve email delivery by verifying the authenticity of emails and ensuring that they come from a trusted sender.
DKIM (DomainKeys Identified Mail) is a method of verifying the authenticity of emails using digital signatures. It involves embedding a digital signature in the header of the email, which is verified by the receiving domain. If the signature is valid, the e-mail is classified as authentic and delivery is facilitated.
SPF (Sender Policy Framework), on the other hand, is a system that prevents emails from being sent from unauthorized servers. It involves creating an entry in the domain’s DNS record that specifies which servers are authorized to send email on behalf of the domain. When the receiving domain verifies that the server sending the email is listed in the SPF record of the sender domain, the email is delivered.
Using DKIM and SPF can improve email delivery because these systems verify the authenticity of the email and ensure that it comes from a trusted sender. This reduces the risk of emails being blocked by spam filters or moved to the spam folder, resulting in a higher delivery rate and improved communication.