Hello First all, this is the enviroment: 3x W2003 Hubcas role servers 5x W2003 Mailbox servers (Lets call them MBX_A) 2x W2003 Domain Controller And on another lan, the drs: 5x W2003 Mailbox Servers (Lets call them MBX_B) 2x W2003 Domain Controller All server are part of the same organization, and between MBX_A and MBX_B there is direct connection with a vpn. The thing is, the public folder replication mail are getting stuck on the mail queue (they replicate from MBX_A to MBX_B). The error we getting is: 451.4.4.0 primary target ip address responded with "421.4.2.1 Unable to connect". attempted failover to alternate host, but that did not succeed. Either there are no alternate hosts, or delivery failed to all alternate hosts. We also replicating the Mail Databases without any problem. Checking the mail getting stuck, the sender is: PUBLIC_BBDD@domainname.local and the recipient PUBLIC_BBDD2@domainname.local Looking into de adsiedit, i see that those address are correct on both public folder databases. We already have create new databse to replicate too, and we the email are getting stuck on the queue. Any tips on how i can continue trying to solve this? Thanks!!!

Is there a firewall between them, especailly one that screws with SMTP to try to make it better or cleaner? If so, open it up so that it doesn't mess with the traffic between the Exchange servers. Another cause for this can be if you've messed with the Default receive connector, such as removing permisisons or setting restrictions.Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

Is there a firewall between them, especailly one that screws with SMTP to try to make it better or cleaner? If so, open it up so that it doesn't mess with the traffic between the Exchange servers. Another cause for this can be if you've messed with the Default receive connector, such as removing permisisons or setting restrictions.Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

Hi Did you try what ED said? Also I found a thread came with the same issue http://social.technet.microsoft.com/forums/en-US/exchangesvrtransport/thread/3ed4492a-f245-4edc-9bc2-6d1a80abba61/ There are two possible solution that you could try 1. Disable TLS in the connector Exchange console-> organization>Send connector>Edge Sync - Site to Internet connector>network tab >Uncheck "Enable Domain Security" 2. Allowing traffic on Port 25 Hope it helps CheersZi Feng TechNet Community Support

Hi Did you try what ED said? Also I found a thread came with the same issue http://social.technet.microsoft.com/forums/en-US/exchangesvrtransport/thread/3ed4492a-f245-4edc-9bc2-6d1a80abba61/ There are two possible solution that you could try 1. Disable TLS in the connector Exchange console-> organization>Send connector>Edge Sync - Site to Internet connector>network tab >Uncheck "Enable Domain Security" 2. Allowing traffic on Port 25 Hope it helps CheersZi Feng TechNet Community Support

Heya Tried everything: The firewall has already all port open (mailbox sync is working) Receive connector is without tls, and allows relay to the servers. But i still getting the same message. i dont know what to try nest, i think i have no more ideas :/

Heya Tried everything: The firewall has already all port open (mailbox sync is working) Receive connector is without tls, and allows relay to the servers. But i still getting the same message. i dont know what to try nest, i think i have no more ideas :/

Mailbox sync doesn't use port 25. I still believe your firewall is interfering with SMTP.Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

Mailbox sync doesn't use port 25. I still believe your firewall is interfering with SMTP.Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."