Mail for example.com is not received without any records in
- The following error can be found on the sender’s side:
connect to example.com[203.0.113.3]:25: Network is unreachable
Where 203.0.113.3 is the IP of ServerShield by Cloudflare extension.
- Port 25 is open on the server:
# nmap -p 25 203.0.113.2 -Pn
PORT STATE SERVICE
25/tcp open smtp
Domain example.com does not have MX record:
# dig MX example.com +short
Missing MX record for example.com
If Plesk DNS server is used, add MX record for the domain using the article: How to add a DNS record for a domain in Plesk?
In case an external DNS server is used, it is required to add the appropriate MX records on the registrar’s side using the article: How to configure mail in Plesk if DNS is hosted externally?
Note: It is required to wait for the DNS propagation period (up to 48 hours, but mostly faster).