Hi folks, i have this issue when i send emails to some external domains; those emails are stuck in the queue viewer of my MS Exchange 2010 server; the detail of the error is "421 Syntax error". The destination email address is correct; and all of my PTR and MX records are correct; in fact with some others domains i'm not having this issue.
I'm desperate to solve this situation because the emails are not being send, outside my organization.
PD: My english is not so well; sorry for that!!..
Thanks in advance. somebody help me!!!.