Can’t send a message to It’s a domino fault! It’s your fault!

Yesterday the users complaim about this and conclude that it's a domino fault and my fault.

For several years I received this type of complaint. Every time I researched the problem I found problems with DNS. Lack of PTR record, MX record in error and ultimately a lack of SPF record. . It's not Domino fault! It's not my fault!

The fault is always (or almost 99%) the network administrators or DNS administrators.

I use the following in my own DNS to avoid problems:

1 - Use the A record pointing to your Domino Server
2 - Create a PTR record for your Domino Server
3- Create a MX record and setup it pointing to the A record of your Domino Server.
4 - Create a SPF record  

Test tool:  Mool BXTox