Error 550 5.7.1 with several mail servers ?

[Samp]

Hi,

We can't send mail on several remote SMTP server we got an 550 5.7.1 error notification:

<mail@domain>: host mail.keysourcerail.com.au[203.161.121.186]
said: 550 5.7.1 Your email messages have been blocked by the recipient OR
by Trend Micro Email Reputation Service. Contact the recipient or his/her
administrator using alternate means to resolve the issue. (in reply to RCPT
TO command)

Or

<mail@free.fr>: host mx1.free.fr[212.27.48.6] said: 554 too many errors
detected from your IP (88.191.228.233), please visit
Postmaster.free.fr (in reply to DATA command)

We never got this before Zimbra.

Please help...

Sam.

[veronica]

Do you have "recipient verification" enabled in zimbra MTA ?

[Samp]

Originally Posted by veronica

Do you have "recipient verification" enabled in zimbra MTA ?

I have :

smtpd_recipient_restrictions = reject_non_fqdn_recipient, permit_sasl_authenticated, permit_mynetworks, reject_unauth_destination, reject_unlisted_recipient, reject_invalid_hostname, reject_non_fqdn_sender, permit

Sam