I send messages to domain ford.com, nutricia.com, mazdaeur.com, uta.com etc.
Each domain reply back "Remote Server at cluster8a.eu.messagelabs.com (85.158.139.103) returned '550 4.4.7 QUEUE.Expired; message expired'" or " Remote Server at cluster8a.eu.messagelabs.com (85.158.139.103) returned '441 4.4.1 Error encountered while communicating with primary target IP address: "421 4.4.2 Connection dropped due to ConnectionReset." Attempted failover to alternate host, but that did not succeed. Either there are no alternate hosts, or delivery failed to all alternate hosts. The last endpoint attempted was 85.158.139.103:25'
When I try list MX record for e.g ford.com DNS returns
cluster4a.us.messagelabs.com internet address = 216.82.251.230
cluster4.us.messagelabs.com internet address = 67.219.247.49
cluster4.us.messagelabs.com internet address = 67.219.246.97
cluster4.us.messagelabs.com internet address = 67.219.251.49
cluster4.us.messagelabs.com internet address = 67.219.250.193
cluster4.us.messagelabs.com internet address = 67.219.250.97
cluster4.us.messagelabs.com internet address = 67.219.246.193
I have 10 mailserver in one subnet 80.188.242.x Any address is not on blacklist http://ipremoval.sms.symantec.com/lookup/
If I try to connect via telnet on port 25 to messagelabs.com from subnet 80.188.242.x I get answer "connection abort" or something similar.
SMTPDiag from one of the servers
Searching for Exchange external DNS settings.
Computer name is MFX.
VSI 1 has the following external DNS servers:
There are no external DNS servers configured.
Checking SOA for ford.com.
Checking external DNS servers.
Checking internal DNS servers.
SOA serial number match: Passed.
Checking local domain records.
Checking MX records using TCP: mf.cz.
Checking MX records using UDP: mf.cz.
Both TCP and UDP queries succeeded. Local DNS test passed.
Checking remote domain records.
Checking MX records using TCP: ford.com.
Checking MX records using UDP: ford.com.
Both TCP and UDP queries succeeded. Remote DNS test passed.
Checking MX servers listed for info@ford.com.
Connecting to cluster4.us.messagelabs.com [67.219.251.49] on port 25.
Error: Expected "250". Server rejected the recipient address.
Failed to submit mail to cluster4.us.messagelabs.com.
Connecting to cluster4.us.messagelabs.com [67.219.250.97] on port 25.
Error: Expected "250". Server rejected the recipient address.
Failed to submit mail to cluster4.us.messagelabs.com.
Connecting to cluster4.us.messagelabs.com [67.219.250.193] on port 25.
Error: Expected "250". Server rejected the recipient address.
Failed to submit mail to cluster4.us.messagelabs.com.
Connecting to cluster4.us.messagelabs.com [67.219.247.49] on port 25.
Error: Expected "250". Server rejected the recipient address.
Failed to submit mail to cluster4.us.messagelabs.com.
Connecting to cluster4.us.messagelabs.com [67.219.246.97] on port 25.
Error: Expected "250". Server rejected the recipient address.
Failed to submit mail to cluster4.us.messagelabs.com.
Connecting to cluster4.us.messagelabs.com [67.219.246.193] on port 25.
Error: Expected "250". Server rejected the recipient address.
Failed to submit mail to cluster4.us.messagelabs.com.
Connecting to cluster4a.us.messagelabs.com [216.82.251.230] on port 25.
Error: Expected "250". Server rejected the recipient address.
Failed to submit mail to cluster4a.us.messagelabs.com.