Remote SMTP Server Returned: 550 relay not permitted
Remote SMTP Server Returned: 550 relay not permitted. This error is a pretty simple from the text. The remote server is not able to receive the email. There may be multiple reasons behind this issue. I would like to list few reasons which can help an IT administrator to solve this issue.
- The client IP address is listed in an email blacklist like barracuda.
- The email server of the client is not able to resolve the target domain correctly.
- The email server of the client is having bad reputation
- SPF record of the sender domain does not allow the sender IP address
1.First check the client IP address against the blacklist by using the URL listed below:
Client IP Address Blacklist Check
If the client’s IP address is listed in any blacklist, first remove the IP address from that blacklist and then try again to send the email. If email is still not working after removing the IP address from the blacklist then follow the second point.
2. The email server of the client is not able to resolve the target domain correctly.
The most obvious reason of the error is that sender email server is not able to correctly resolve the target domain name to a valid IP address of the target server. In my case this was the issue. I follow under listed method to resolve it.
Go to Run and enter CMD
open CMD with administrator privileges
write ipconfig/flushdns command and press enter
write ipconfig/registerdns command and press enter.
Go to the email server and try to ping the target email server like gmail.com and check if you are able to get the correct IP address. Once you are done with the IP configuration your email start working.
3. There might be a chance that client’s email server is having very bad reputation of sending spam emails. in this case you need to fix the reputation by following the best practices listed in the URL below:
4. If there is an SPF record configured for the domain and its strict in sending the email. you need to ask the server admin to add your IP address in the SPF record.
