we have a user on Exchange 2010 server who doesn't get email from one specific domain if her address is in cc: field. If she is a main recipient (To:) it goes through. We checked Exchange logs and it looks like our server doesn't even try to deliver it, it simply ignores her email address completely.
We did several tests:
- send email with her email address in cc: field from another domain, succeeded
- send email with her email address in to: field from another domain, succeeded
- send email with her email address in to: field from affected domain, succeeded
- turn off all email rules
- check via webmail
We also turned off firewall, antispam and antivirus for SMTP rule.
Does anyone have any idea what could be an issue here?