Testing Dovecot

netstat test

Now that almost all services are installed, you may want to check that all ports related to your mail server are open as expected:

# netstat -plntu
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name 
tcp 0 0 0.0.0.0:110 0.0.0.0:* LISTEN 17141/dovecot 
tcp 0 0 127.0.0.1:3310 0.0.0.0:* LISTEN 15754/clamd 
tcp 0 0 0.0.0.0:143 0.0.0.0:* LISTEN 17141/dovecot 
tcp 0 0 0.0.0.0:89 0.0.0.0:* LISTEN 17120/tcpserver 
tcp 0 0 0.0.0.0:25 0.0.0.0:* LISTEN 17118/tcpserver 
tcp 0 0 0.0.0.0:4190 0.0.0.0:* LISTEN 17141/dovecot 
tcp 0 0 0.0.0.0:993 0.0.0.0:* LISTEN 17141/dovecot 
tcp 0 0 0.0.0.0:995 0.0.0.0:* LISTEN 17141/dovecot 
tcp 0 0 0.0.0.0:587 0.0.0.0:* LISTEN 17117/tcpserver

Testing POP3

Remember that plain text login is allowed only from localhost.

# telnet [your-IP] 110
Trying [your-IP]...
Connected to [your-IP].
Escape character is '^]'.
+OK Dovecot ready.
user test@yourdomain.net
+OK
pass [PASSWORD]
+OK Logged in.
quit
+OK Logging out.
Connection closed by foreign host.

Check also the secure POP connection on port 995

openssl s_client -connect [your-IP]:995

Testing IMAP

Now let's test the IMAP server. This plain text login test is allowed only from localhost.

# telnet [your-IP] 143
Trying [your-IP]...
Connected to [your-IP].
Escape character is '^]'.
* OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE STARTTLS AUTH=PLAIN AUTH=LOGIN AUTH=DIGEST-MD5 AUTH=CRAM-MD5] Dovecot ready.
a login test@yourdomain.net [PASSWORD]
a OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE SORT SORT=DISPLAY THREAD=REFERENCES THREAD=REFS MULTIAPPEND UNSELECT IDLE CHILDREN NAMESPACE UIDPLUS LIST-EXTENDED I18NLEVEL=1 CONDSTORE QRESYNC ESEARCH ESORT SEARCHRES WITHIN CONTEXT=SEARCH LIST-STATUS QUOTA] Logged in
a select inbox
* FLAGS (\Answered \Flagged \Deleted \Seen \Draft)
* OK [PERMANENTFLAGS (\Answered \Flagged \Deleted \Seen \Draft \*)] Flags permitted.
* 0 EXISTS
* 0 RECENT
* OK [UIDVALIDITY 1287576448] UIDs valid
* OK [UIDNEXT 1] Predicted next UID
* OK [HIGHESTMODSEQ 1] Highest
a OK [READ-WRITE] Select completed.
a list "" *
* LIST (\HasNoChildren) "." "INBOX"
a OK List completed.
a GETQUOTA "" 
* QUOTA "" (STORAGE 29620 409600) 
a OK Getquota completed (0.001 + 0.000 secs).
a logout
* BYE Logging out
a OK Logout completed.
Connection closed by foreign host.

We have tested both the connection and if the server can find the mailbox. As you can see the only folder is  INBOX.

Test now the secure connection to IMAP:

openssl s_client -connect [your-IP]:993

openssl s_client -connect localhost:995 -CApath /etc/ssl/certs

telnet localhost 110
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
+OK Dovecot ready.
user wangyouyu@wangyouyu.com
+OK
pass 143youyu143
-ERR [SYS/TEMP] Temporary authentication failure. [iZ25orcjh1sZ:2015-11-22 09:51:45]

user wangyy@wangyouyu.com
+OK
pass mypassword
-ERR [SYS/TEMP] Temporary authentication failure. [iZ25orcjh1sZ:2015-11-22 09:49:35]

./configure \
        --enable-qmaildir=/var/qmail/ \
        --enable-qmail-newu=/var/qmail/bin/qmail-newu \
        --enable-qmail-inject=/var/qmail/bin/qmail-inject \
        --enable-qmail-newmrh=/var/qmail/bin/qmail-newmrh \
        --disable-roaming-users \
        --enable-incdir=/usr/include/mysql \
        --enable-libdir=/usr/lib64/mysql \
        --enable-logging=p \
        --disable-clear-passwd \
        --enable-auth-logging \
        --disable-valias \
        --disable-mysql-limits \
        --disable-passwd \
        --enable-qmail-ext \
        --enable-learn-passwords