Accepting "null sender" addresses?

[diginfo]

Hi,

My domain authority demands that I setup our e-mailserver so that it accepts messages with "null sender addresses". This is due to null sender addresses being something that is used to verify the validity of DSN's in the domain name system.

How can I setup Ability Mail server to accept <>@digitalinformation.se type addresses?

Thank you for your support!

Petter Sehlin
Sweden

[Code Crafters]

I don't think that an email address of that format is actually a legal format according to the official domain and email format RFCs. You may use the following fomats that our mail server does support:

user@domain
user@domain.com
[1.2.3.4]@domain.com
<user@domain.com>
"personal name" <user@domain.com>
<>

The last example is a true NULL sender which should be used when no return address is to be used. Be aware that often DNS servers use irregular formats that no legitimate email would use and often these aren't allowed for security reasons such as probing for mail server account information existing etc and this doesn't mean that there is anything wrong with how your mail server will operate. The best thing to do would be to send your SMTP log showing this test activity to chris@code-crafters.com and I'll look at the log and see if I can see the usage and format of this more clearly to see what action can be taken to allow this.