[BlueOnyx:21475] Email delivery issue

[Colin Jack]

Hoping someone can give me some pointers please ...

We have a number of users on our fast-mail.net domain who say that email to outlook.com and hotmail.com email addresses (so basically Microsoft) are not being delivered or bounced.

The server is a standard 5207R box ... mail is received and sent off the same server.

Not on any RBLs that I can see and SPF checks out okay.

Just wondering where to look next.

Thanks

Colin