I have a system to send a mail to the users who are all using different mail clients like Gmail, Outlook, Rediff etc. But, I am using a From address as constant string (mrblack) instead of an email format (mrblack@example.com).
Outlook and Rediff cannot receive these emails, while other mail servers are getting them fine.
What do I need to add/change in any header sections in my mail process (without changing from address)? Or is there any configuration in outlook.com to receive an email from a sender without the traditional email format address?
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Best Answer
If I understand you correctly, you are using a FROM address in the form "mrblack"?
I believe that breaks RFC 2822 and so there is no guarantee that ANY client will accept it.
You need to put your FROM address text into the correct RFC format.