Issue No e-mails to Hotmail/t-online/ possible

[anonymuserok]

Hello,
i am new here
and i have a problem with Send e-mails to Hotmail or t-online


i get this error message from Hotmail

Undelivered Mail Returned to Sender
This is the mail system at host

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.


And from t-online
they do not receive e -mails
when i send a e-mail the user dont get the e-mail

can you help me?

Thanks

 

[Bitpalast]

Your server IP might be blacklisted. What errors are logged in your /var/log/maillog on these messages?

 

[SimonG]

Check for blacklisting of your IP address(es). I usually use MX Toolbox.
For the Microsoft services like Hotmail, try registering with SNDS if you can.
MS Smart Network Data Services (SNDS)

If you haven't already done so, make sure your server has a fully qualified hostname, and that you have ReverseDNS/PTR set for your server's IPs.