OPS335 Dovecot

Configuration for IMAP and POP3

• Edit the configuration file /etc/dovecot/dovecot.conf, and add the following line to the bottom of the file, or uncomment the same line in /etc/dovecot/conf.d/10-mail.conf:

mail_location = mbox:~/mail:INBOX=/var/mail/%u

• Change the access permission of user mail box in /var/mail from 660 to 600 with the following command:

chmod 600 /var/mail/*

Testing POP3 port 110

• Login to your POP3 server as a regular user.
• telnet 192.168.122.184 110

The following is a typical successful POP3 session:

[rchan@f16 ~]$ telnet localhost 110
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
+OK Dovecot ready.
USER ops335
+OK
PASS seneca99
+OK Logged in.
LIST
+OK 2 messages:
1 750
2 796
.
QUIT
+OK Logging out.
Connection closed by foreign host.

In the above POP3 session, Four POP3 commands were used to verify that the POP3 server was running properly, they are: USER, PASS, LIST, and QUIT.

• USER: Followed by the user/owner name of the mail box
• PASS: Password associated with the user name
• LIST: Give a list of the email in the user's mail box and the size (in bytes) of each email.
• QUIT: Terminate the POP3 session.

Note that the user name and password were send in clear text to the POP3 server. In this sample session, both the POP3 server and the POP3 client (done manually using telnet) were on the same system.

Testing POP3 port 995

• openssl s_client -connect 192.168.122.184:995

The following is a sample POP3S session:

[root@rchan ~]# openssl s_client -connect 192.168.122.184:995
CONNECTED(00000003)
depth=0 OU = IMAP server, CN = imap.example.com, emailAddress =  postmaster@example.com
verify error:num=18:self signed certificate
verify return:1
depth=0 OU = IMAP server, CN = imap.example.com, emailAddress =  postmaster@example.com
verify return:1
---
Certificate chain
 0 s:/OU=IMAP server/CN=imap.example.com/emailAddress=postmaster@example.com
  i:/OU=IMAP server/CN=imap.example.com /emailAddress=postmaster@example.com
---
Server certificate
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
subject=/OU=IMAP server/CN=imap.example.com /emailAddress=postmaster@example.com
issuer=/OU=IMAP server/CN=imap.example.com /emailAddress=postmaster@example.com
---
No client certificate CA names sent
---
SSL handshake has read 1301 bytes and written 311 bytes
---
New, TLSv1/SSLv3, Cipher is DHE-RSA-AES256-SHA
Server public key is 1024 bit
Secure Renegotiation IS supported
Compression: zlib compression
Expansion: zlib compression
SSL-Session:
   Protocol  : TLSv1
   Cipher    : DHE-RSA-AES256-SHA
   Session-ID: 7D2FAD3059BB443857C4FC5766F55E2AF58DC0612E884A12918C84F409C63C85
   Session-ID-ctx:
   Master-Key: 897A5BB65CA9542E502FAFCDEF3918C13BC6C42721BD60443311D1FDD7DA691C0DDA17FB284ADA74083D1ADB2A2B4265
   Key-Arg   : None
   Krb5 Principal: None
   PSK identity: None
   PSK identity hint: None
   TLS session ticket:
   0000 - 06 ef d1 c5 22 bb 33 30-8f 6a de 1e 5f 7b 03 55   ....".30.j.._{.U
   0010 - 30 d3 3b 67 21 ed 34 1a-dd 50 43 25 fe 45 16 b7   0.;g!.4..PC%.E..
   0020 - 5b d3 0f 9b f8 59 04 b6-3a 6c 2c 8b 13 4f c8 54   [....Y..:l,..O.T
   0030 - 77 fa e1 3f 47 f9 fc 3a-72 f8 4e 21 e1 e9 b3 3d   w..?G..:r.N!...=
   0040 - 08 be d5 83 50 91 48 d7-03 09 f7 2b ae a7 81 9c   ....P.H....+....
   0050 - 23 53 48 a2 38 06 69 3c-a8 c3 4b 16 e2 e8 15 eb   #SH.8.i<..K.....
   0060 - 13 8d 83 b0 13 cb ac 98-76 25 da 69 fd 2a 64 aa   ........v%.i.*d.
   0070 - 2c dd 1a e5 e2 61 4c 9a-93 d6 d8 1b 56 be 44 00   ,....aL.....V.D.
   0080 - 53 bd 28 b1 5a c4 5d 42-df 67 89 89 56 65 aa 95    S.(.Z.]B.g..Ve..
   0090 - 10 29 cc 18 be 52 b8 c8-eb 7e 74 46 9e be 57 39     .)...R...~tF..W9

   Compression: 1 (zlib compression)
   Start Time: 1329218719
   Timeout   : 300 (sec)
   Verify return code: 18 (self signed certificate)
---
+OK OPS335 Dovecot ready.
USER ops335
+OK
PASS seneca99
+OK Logged in.
LISt
+OK 1 messages:
1 722
.
QUIT
DONE

Testing IMAP port 143

• telnet 192.168.122.184 143

Testing IMAP port 993

• openssl s_client -connect 192.168.122.184:993