I have this same problem. Last night my server stopped sending/receiving mail. I have gone through this post and many other and have not yet found an answer for this problem. I could not find anything in the logs which indicated a problem. Below is output from the commands requested in this and other posts.



[zimbra@zimbra ~]$ cat /etc/hosts
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1 localhost.localdomain localhost
172.20.1.4 zimbra.monafamily.com zimbra
[zimbra@zimbra ~]$ cat /etc/resolv.conf
search monafamily.com
nameserver 172.20.1.4
#nameserver 172.20.1.1
#nameserver 172.20.1.2
[zimbra@zimbra ~]$ dig monafamily.com mx

; <<>> DiG 9.3.6-P1-RedHat-9.3.6-4.P1.el5_4.1 <<>> monafamily.com mx
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 26221
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2

;; QUESTION SECTION:
;monafamily.com. IN MX

;; ANSWER SECTION:
monafamily.com. 86400 IN MX 10 zimbra.monafamily.com.

;; AUTHORITY SECTION:
monafamily.com. 86400 IN NS ns1.commpartners.us.
monafamily.com. 86400 IN NS ns1.monafamily.com.

;; ADDITIONAL SECTION:
zimbra.monafamily.com. 86400 IN A 172.20.1.4
ns1.commpartners.us. 42686 IN A 204.14.36.99

;; Query time: 1 msec
;; SERVER: 172.20.1.4#53(172.20.1.4)
;; WHEN: Wed Jan 20 10:07:52 2010
;; MSG SIZE rcvd: 138

[zimbra@zimbra ~]$ dig monafamily.com any

; <<>> DiG 9.3.6-P1-RedHat-9.3.6-4.P1.el5_4.1 <<>> monafamily.com any
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 7616
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 2

;; QUESTION SECTION:
;monafamily.com. IN ANY

;; ANSWER SECTION:
monafamily.com. 86400 IN SOA monafamily.com. webmaster.monafamily.com. 2009123100 3600 600 604800 3600
monafamily.com. 86400 IN NS ns1.monafamily.com.
monafamily.com. 86400 IN NS ns1.commpartners.us.
monafamily.com. 86400 IN MX 10 zimbra.monafamily.com.
monafamily.com. 86400 IN A 172.20.1.4

;; ADDITIONAL SECTION:
ns1.commpartners.us. 42680 IN A 204.14.36.99
zimbra.monafamily.com. 86400 IN A 172.20.1.4

;; Query time: 1 msec
;; SERVER: 172.20.1.4#53(172.20.1.4)
;; WHEN: Wed Jan 20 10:07:58 2010
;; MSG SIZE rcvd: 200

[zimbra@zimbra ~]$ host `hostname`
zimbra.monafamily.com has address 172.20.1.4
[zimbra@zimbra ~]$
[zimbra@zimbra ~]$ zmcontrol -v


Release 6.0.4_GA_2038.RHEL5_20091214191028 CentOS5 FOSS edition.
[zimbra@zimbra ~]$ postfix check
postfix/postfix-script: warning: not owned by root: /opt/zimbra/data/postfix/spool
postfix/postfix-script: warning: not owned by root: /opt/zimbra/postfix-2.6.5.2z/conf/main.cf
postfix/postfix-script: warning: not owned by root: /opt/zimbra/postfix-2.6.5.2z/conf/master.cf
postfix/postfix-script: warning: not owned by root: /opt/zimbra/postfix-2.6.5.2z/conf/master.cf.in
[zimbra@zimbra ~]$
[zimbra@zimbra ~]$ ps aux | grep zimbra
avahi 2431 0.0 0.0 2600 1376 ? Ss 09:59 0:00 avahi-daemon: running [zimbra.local]
zimbra 2547 0.2 1.4 137744 30240 ? Ssl 09:59 0:01 /opt/zimbra/openldap/sbin/slapd -l LOCAL0 -4 -u zimbra -h ldap://zimbra.monafamily.com:389 ldapi:/// -F /opt/zimbra/data/ldap/config
zimbra 4450 0.0 0.2 8792 5896 ? Ss 10:00 0:00 /opt/zimbra/libexec/logswatch --config-file=/opt/zimbra/conf/logswatchrc --use-cpan-file-tail --pid-file=/opt/zimbra/log/logswatch.pid --daemon --script-dir=/opt/zimbra/data/tmp -t /var/log/zimbra-stats.log
zimbra 4451 0.0 0.2 18792 5804 ? S 10:00 0:00 /usr/bin/perl /opt/zimbra/libexec/zmlogger
zimbra 4568 0.0 0.1 7800 3928 ? S 10:00 0:00 zmlogger: zmrrdfetch: server
zimbra 4577 0.1 0.3 10068 7420 ? S 10:00 0:00 /usr/bin/perl /opt/zimbra/libexec/zmmtaconfig
zimbra 4594 0.0 0.0 2560 1112 ? S 10:00 0:00 /bin/sh /opt/zimbra/mysql/bin/mysqld_safe --defaults-file=/opt/zimbra/conf/my.cnf --external-locking --log-error=/opt/zimbra/log/mysql_error.log --ledir=/opt/zimbra/mysql/libexec
zimbra 4734 0.4 4.0 287976 83852 ? Sl 10:00 0:02 /opt/zimbra/mysql/libexec/mysqld --defaults-file=/opt/zimbra/conf/my.cnf --basedir=/opt/zimbra/mysql --datadir=/opt/zimbra/db/data --pid-file=/opt/zimbra/db/mysql.pid --skip-external-locking --port=7306 --socket=/opt/zimbra/db/mysql.sock --external-locking
root 6822 0.0 0.0 1660 388 ? Ss 10:02 0:00 /opt/zimbra/libexec/zmmailboxdmgr start -server -Djava.awt.headless=true -XX:+UseConcMarkSweepGC -XX:NewRatio=2 -XX:PermSize=128m -XX:MaxPermSize=128m -XX:SoftRefLRUPolicyMSPerMB=1 -verbose:gc -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintGCApplicationStoppedTime -Xss256k -Xms810m -Xmx810m -Xmn202m
zimbra 6823 29.3 16.6 1154860 346232 ? Sl 10:02 2:12 /opt/zimbra/java/bin/java -server -Djava.awt.headless=true -XX:+UseConcMarkSweepGC -XX:NewRatio=2 -XX:PermSize=128m -XX:MaxPermSize=128m -XX:SoftRefLRUPolicyMSPerMB=1 -verbose:gc -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintGCApplicationStoppedTime -Xss256k -Xms810m -Xmx810m -Xmn202m -Djava.io.tmpdir=/opt/zimbra/mailboxd/work -Djava.library.path=/opt/zimbra/lib -Djava.endorsed.dirs=/opt/zimbra/mailboxd/common/endorsed -Dzimbra.config=/opt/zimbra/conf/localconfig.xml -Djetty.home=/opt/zimbra/mailboxd -DSTART=/opt/zimbra/mailboxd/etc/start.config -jar /opt/zimbra/mailboxd/start.jar /opt/zimbra/mailboxd/etc/jetty.properties /opt/zimbra/mailboxd/etc/jetty-setuid.xml /opt/zimbra/mailboxd/etc/jetty.xml
zimbra 7024 0.3 2.5 62088 52704 ? Ss 10:02 0:01 amavisd (master)
zimbra 7071 0.0 2.4 62088 51328 ? S 10:02 0:00 amavisd (virgin child)
zimbra 7072 0.0 2.4 62088 51300 ? S 10:02 0:00 amavisd (virgin child)
zimbra 7073 0.0 2.4 62088 51300 ? S 10:02 0:00 amavisd (virgin child)
zimbra 7074 0.0 2.4 62088 51300 ? S 10:02 0:00 amavisd (virgin child)
zimbra 7075 0.0 2.4 62088 51300 ? S 10:02 0:00 amavisd (virgin child)
zimbra 7076 0.0 2.4 62088 51300 ? S 10:02 0:00 amavisd (virgin child)
zimbra 7079 0.0 2.4 62088 51300 ? S 10:02 0:00 amavisd (virgin child)
zimbra 7080 0.0 2.4 62088 51300 ? S 10:02 0:00 amavisd (virgin child)
zimbra 7081 0.0 2.4 62088 51300 ? S 10:02 0:00 amavisd (virgin child)
zimbra 7082 0.0 2.4 62088 51300 ? S 10:02 0:00 amavisd (virgin child)
zimbra 7118 0.0 0.0 3116 1356 ? Ss 10:02 0:00 /opt/zimbra/clamav/bin/freshclam --config-file=/opt/zimbra/conf/freshclam.conf --quiet --daemon --checks=12
zimbra 7432 0.0 4.2 100536 87932 ? Ssl 10:02 0:00 /opt/zimbra/clamav/sbin/clamd --config-file=/opt/zimbra/conf/clamd.conf
zimbra 7456 0.0 0.2 6748 4828 ? S 10:02 0:00 /usr/bin/perl /opt/zimbra/libexec/swatch --config-file=/opt/zimbra/conf/swatchrc --use-cpan-file-tail --script-dir=/opt/zimbra/data/tmp -t /var/log/zimbra.log
zimbra 7476 0.0 0.3 8796 6724 ? S 10:02 0:00 /usr/bin/perl /opt/zimbra/data/tmp/.swatch_script.7456
zimbra 7514 0.0 0.3 12304 6684 ? Ss 10:02 0:00 /opt/zimbra/httpd-2.2.14/bin/httpd -k start -f /opt/zimbra/conf/httpd.conf
zimbra 7529 0.0 0.3 14796 7716 ? S 10:02 0:00 /opt/zimbra/httpd-2.2.14/bin/httpd -k start -f /opt/zimbra/conf/httpd.conf
zimbra 7530 0.0 0.2 12304 6056 ? S 10:02 0:00 /opt/zimbra/httpd-2.2.14/bin/httpd -k start -f /opt/zimbra/conf/httpd.conf
zimbra 7531 0.0 0.2 12304 6056 ? S 10:02 0:00 /opt/zimbra/httpd-2.2.14/bin/httpd -k start -f /opt/zimbra/conf/httpd.conf
zimbra 7532 0.0 0.2 12304 6056 ? S 10:02 0:00 /opt/zimbra/httpd-2.2.14/bin/httpd -k start -f /opt/zimbra/conf/httpd.conf
zimbra 7533 0.0 0.2 12304 6056 ? S 10:02 0:00 /opt/zimbra/httpd-2.2.14/bin/httpd -k start -f /opt/zimbra/conf/httpd.conf
zimbra 7647 0.0 0.0 7436 804 ? Ss 10:02 0:00 /opt/zimbra/cyrus-sasl/sbin/saslauthd -r -a zimbra
zimbra 7651 0.0 0.0 7436 552 ? S 10:02 0:00 /opt/zimbra/cyrus-sasl/sbin/saslauthd -r -a zimbra
zimbra 7652 0.0 0.0 7436 540 ? S 10:02 0:00 /opt/zimbra/cyrus-sasl/sbin/saslauthd -r -a zimbra
zimbra 7653 0.0 0.0 7436 540 ? S 10:02 0:00 /opt/zimbra/cyrus-sasl/sbin/saslauthd -r -a zimbra
zimbra 7654 0.0 0.0 7436 540 ? S 10:02 0:00 /opt/zimbra/cyrus-sasl/sbin/saslauthd -r -a zimbra
zimbra 7990 0.0 0.2 6684 4792 ? S 10:03 0:00 /usr/bin/perl -w /opt/zimbra/libexec/zmstat-proc
zimbra 7992 0.0 0.2 6432 4580 ? S 10:03 0:00 /usr/bin/perl -w /opt/zimbra/libexec/zmstat-cpu
zimbra 7994 0.0 0.2 6432 4584 ? S 10:03 0:00 /usr/bin/perl -w /opt/zimbra/libexec/zmstat-vm
zimbra 7996 0.0 0.2 6432 4652 ? S 10:03 0:00 /usr/bin/perl -w /opt/zimbra/libexec/zmstat-io -x
zimbra 7998 0.0 0.2 6432 4452 ? S 10:03 0:00 /usr/bin/perl -w /opt/zimbra/libexec/zmstat-df
zimbra 8000 0.0 0.2 6432 4584 ? S 10:03 0:00 /usr/bin/perl -w /opt/zimbra/libexec/zmstat-io
zimbra 8002 0.0 0.2 6428 4516 ? S 10:03 0:00 /usr/bin/perl -w /opt/zimbra/libexec/zmstat-fd
zimbra 8004 0.4 0.2 7132 5180 ? S 10:03 0:01 /usr/bin/perl -w /opt/zimbra/libexec/zmstat-allprocs
zimbra 8006 0.0 0.2 6568 4696 ? S 10:03 0:00 /usr/bin/perl -w? /opt/zimbra/libexec/zmstat-mysql
zimbra 8109 0.0 0.2 6432 4556 ? S 10:03 0:00 /usr/bin/perl -w /opt/zimbra/libexec/zmstat-mtaqueue
zimbra 8698 0.0 0.0 1688 456 ? S 10:03 0:00 /usr/bin/vmstat -n -S K 30
zimbra 8699 0.0 0.0 1700 612 ? S 10:03 0:00 /usr/bin/iostat -d -k 30
zimbra 8704 0.0 0.0 1700 644 ? S 10:03 0:00 /usr/bin/iostat -d -k -x 30
root 9822 0.0 0.0 4920 1268 pts/0 S 10:04 0:00 su - zimbra
zimbra 9823 0.0 0.0 4660 1504 pts/0 S 10:04 0:00 -bash
zimbra 11508 0.0 0.2 12304 6056 ? S 10:06 0:00 /opt/zimbra/httpd-2.2.14/bin/httpd -k start -f /opt/zimbra/conf/httpd.conf
zimbra 13815 3.3 0.7 411048 15804 ? Sl 10:09 0:00 /opt/zimbra/java/bin/java -XX:ErrorFile=/opt/zimbra/log -client -Xmx256m -Dzimbra.home=/opt/zimbra -Djava.library.path=/opt/zimbra/lib -Djava.ext.dirs=/opt/zimbra/java/jre/lib/ext:/opt/zimbra/lib/jars:/opt/zimbra/lib/ext-common:/opt/zimbra/lib/ext/clamscanner com.zimbra.cs.account.ProvUtil -l gs zimbra.monafamily.com
zimbra 13987 0.0 0.0 2184 820 pts/0 R+ 10:09 0:00 ps aux
zimbra 13988 0.0 0.0 1844 476 pts/0 R+ 10:09 0:00 grep zimbra
[zimbra@zimbra ~]$
[zimbra@zimbra ~]$ zmmtactl stop
Stopping zmmtaconfig...done.
postfix/postfix-script: fatal: the Postfix mail system is not running
Stopping saslauthd...done.
[zimbra@zimbra ~]$ zmmtactl start
Rewriting configuration files...done.
Starting zmmtaconfig...done.
Starting saslauthd...done.
[zimbra@zimbra ~]$