We are having trouble with our cPanel email on our domain whereby one recipient does not receive most of our emails. Everyone else does on various accounts such as outlook.com, gmail.com etc.
The particular recipient is hosted by IONAS and the user has contacted their support to ask if they can see any blocking and errors at their end. They are saying its an error in the GoDaddy MX Record. I have contacted GoDaddy support and they say there is no issue at their end with their response:
Yes, cause I can see here that there's no issues on our mail server. Thehomestartcolevalley.org.uk is blocking thehomestartbirmingham.co.uk . Therefore, the issues is not with you . Yes cause you are able to send emails except to homestartcolevalley.org.uk. Therefore,homestartcolevalley.org.ukneeds to be whitelisthomestartbirmingham.co.uk because it's blocking your domain. And I can assure you that there's no problem with our mail server.
Here is the response from IONAS (apologies for wall of text):
We sincerely apologize for the inconvenience. However, yes GoDaddy may deny that they do not have issues in their end but as we checked further it appears that they have not configured their mail severs and DNS very well.
As checked, their MX record is not configured properly.
If we check the MX record that is being used mail.homestartbirmingham.co.uk. it will display this result [mail.homestartbirmingham.co.uk has address 188.8.131.52].
Now if we do reverse lookup using the IP address 184.108.40.206 it should supposedly display FQDN (fully qualified domain names). [to know more about FQDNs - https://kb.iu.edu/d/aiuv]
Here's the result: 10.16.153.160.in-addr.arpa domain name pointer ip-160-153-16-10.ip.secureserver.net. <------------- This is the result when it is not properly configured. Result does not display the FQDN.
To give comparison and example of properly configured MX record, we will do the same test to your domain which is hosted with us:
homestartcolevalley.org.uk mail is handled by 10 mx00.1and1.co.uk.
mx00.1and1.co.uk has address 220.127.116.11
Reverse Lookup result: 18.104.22.168.in-addr.arpa domain name pointer mx00.kundenserver.de.
mx00.kundenserver.de is the FQDN for your MX record.
The reason why we are doing this test and talking about misconfigured MX and FQDNS, it is because misconfigured MX records will result to issues and errors. You may relay our reply to GoDaddy so that they can check and correct not only their settings but their statement as well. Hopefully they have the technical knowledge to check on these things and of course we do hope that they are aware of the RFC rule for email.
We have just used the defaults as setup when the email addresses were created and the MX Record is:
Can anybody advise if what they are saying is true as we are caught between the two companies denying its their problem.