0
votes
1answer
122 views

Spam sent from fake email accounts on my domain [duplicate]

One of my clients is getting thousands of "Delivery Status Notification (Failure)" emails per day and it's replied to random email accounts that don't exist on the domain. The content of the emails ...
3
votes
5answers
3k views

Hotmail Sender ID always fails with “temperror” regardless of SPF

When we send mail to Hotmail servers, they do not recognize our Sender ID. In the receiving mail source, it reads Authentication-Results: hotmail.com; sender-id=temperror ... when it should say pass ...
0
votes
1answer
105 views

What is the best approach for setting up a good, secure smtp server on Debian?

Which server do you recommend? (postfix?) Which configuration for authenticating users for sending mail? Which setups for making it inbox friendly (dkim, spf, domainkey etc)? Is there some detailed ...
2
votes
2answers
218 views

How important is sender validation, and what matters?

When I started learning how to configure email, SPF existed but there were doubts about whether it was a good thing, and the value of offering SPF records in DNS. Now it seems that it is widely ...