topic Re: Error 421 SMTP Connection went away in Network Security https://community.cisco.com/t5/network-security/error-421-smtp-connection-went-away/m-p/1765107#M495995 <HTML><HEAD></HEAD><BODY><P>Hi,</P><P></P><P>Pb resolved. I disabled ESMTP inspection. Thanks</P></BODY></HTML> Thu, 20 Oct 2011 18:18:29 GMT avburren1 2011-10-20T18:18:29Z Error 421 SMTP Connection went away https://community.cisco.com/t5/network-security/error-421-smtp-connection-went-away/m-p/1765104#M495989 <P>Hello,</P><P></P><P>I 've got some problem with my Mail Server since I've migrated to an ASA5510.<BR />Actually the server is in a DMZ with a private Ip ( 10.x.x.2) and it is translated to a Public IP ( 194.x.x.65).<BR />I use these configuration :</P><P>static (DMZ,LAN) 194.x.x.65 10.x.x.2 netmask 255.255.255.255 <BR />static (DMZ,LAN) 194.x.x.66 10.x.x.3 netmask 255.255.255.255 <BR />static (DMZ,WAN) 194.x.x.65 10.x.x.2 netmask 255.255.255.255 <BR />static (DMZ,WAN) 194.x.x.66 10.x.x.3 netmask 255.255.255.255 <BR />static (LAN,DMZ) 192.168.0.0 192.168.0.0 netmask 255.255.248.0 </P><P></P><P>Some Users received in there mailbox a system administor error message :</P><P>Object : Impossible to deliver : test<BR />Your message could not be deliver to one or more of its recipients: 421 SMTP connection went away!</P><P></P><P>When they try to re sent it some times later, message is sent whithout problem.</P><P>Any Ideas about it ?</P> Mon, 11 Mar 2019 21:36:27 GMT https://community.cisco.com/t5/network-security/error-421-smtp-connection-went-away/m-p/1765104#M495989 avburren1 2019-03-11T21:36:27Z Error 421 SMTP Connection went away https://community.cisco.com/t5/network-security/error-421-smtp-connection-went-away/m-p/1765105#M495990 <HTML><HEAD></HEAD><BODY><P>no one? Could it be the ESMTP inspection to disable?</P></BODY></HTML> Thu, 13 Oct 2011 11:21:57 GMT https://community.cisco.com/t5/network-security/error-421-smtp-connection-went-away/m-p/1765105#M495990 avburren1 2011-10-13T11:21:57Z Re: Error 421 SMTP Connection went away https://community.cisco.com/t5/network-security/error-421-smtp-connection-went-away/m-p/1765106#M495992 <HTML><HEAD></HEAD><BODY><P>pls post the output of show asp drop</P><P></P><P>Sent from Cisco Technical Support iPhone App</P></BODY></HTML> Thu, 20 Oct 2011 17:53:12 GMT https://community.cisco.com/t5/network-security/error-421-smtp-connection-went-away/m-p/1765106#M495992 iazazkhan 2011-10-20T17:53:12Z Re: Error 421 SMTP Connection went away https://community.cisco.com/t5/network-security/error-421-smtp-connection-went-away/m-p/1765107#M495995 <HTML><HEAD></HEAD><BODY><P>Hi,</P><P></P><P>Pb resolved. I disabled ESMTP inspection. Thanks</P></BODY></HTML> Thu, 20 Oct 2011 18:18:29 GMT https://community.cisco.com/t5/network-security/error-421-smtp-connection-went-away/m-p/1765107#M495995 avburren1 2011-10-20T18:18:29Z