§2024-04-24

ChatGPT

To install Dovecot on Ubuntu, you can follow these steps:

  1. Update Package Lists: Before installing any new software, it's a good practice to update the package lists to ensure you're installing the latest versions of packages.

    • sudo apt update

  2. Install Dovecot: Use the apt package manager to install Dovecot.

    • sudo apt install dovecot-core dovecot-imapd dovecot-pop3d
    • check installation sudo systemctl status dovecot
    alexlai@h2Jammy:~$ systemctl status  dovecot
● dovecot.service - Dovecot IMAP/POP3 email server
     Loaded: loaded (/lib/systemd/system/dovecot.service; enabled; vendor preset: enabled)
     Active: active (running) since Wed 2024-04-24 15:08:38 CST; 39s ago
       Docs: man:dovecot(1)
             https://doc.dovecot.org/
   Main PID: 52605 (dovecot)
     Status: "v2.3.16 (7e2e900c1a) running"
      Tasks: 4 (limit: 9222)
     Memory: 3.2M
        CPU: 67ms
     CGroup: /system.slice/dovecot.service
             ├─52605 /usr/sbin/dovecot -F
             ├─52607 dovecot/anvil
             ├─52608 dovecot/log
             └─52609 dovecot/config

 四  24 15:08:38 h2Jammy systemd[1]: Starting Dovecot IMAP/POP3 email server...
 四  24 15:08:38 h2Jammy dovecot[52605]: master: Dovecot v2.3.16 (7e2e900c1a) starting up for imap, pop3 (core dumps disabled)
 四  24 15:08:38 h2Jammy systemd[1]: Started Dovecot IMAP/POP3 email server.

  3. test pop3,

Authentication Issue: The POP3 server is configured to disallow plaintext authentication on non-secure (SSL/TLS) connections. This means that you cannot authenticate using plaintext (username and password) unless you establish an SSL/TLS connection. You have to use openssl s_client -connect h2jammy.yushei.net:995

alexlai@opi58G:~$ openssl s_client -connect h2jammy.yushei.net:995
CONNECTED(00000003)
depth=0 CN = ubuntu-budgie.munetaka.me
verify error:num=18:self-signed certificate
verify return:1
depth=0 CN = ubuntu-budgie.munetaka.me
verify return:1
---
Certificate chain
 0 s:CN = ubuntu-budgie.munetaka.me
   i:CN = ubuntu-budgie.munetaka.me
   a:PKEY: rsaEncryption, 2048 (bit); sigalg: RSA-SHA256
   v:NotBefore: Aug 17 02:54:00 2022 GMT; NotAfter: Aug 14 02:54:00 2032 GMT
---
Server certificate
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
subject=CN = ubuntu-budgie.munetaka.me
issuer=CN = ubuntu-budgie.munetaka.me
---
No client certificate CA names sent
Peer signing digest: SHA256
Peer signature type: RSA-PSS
Server Temp Key: X25519, 253 bits
---
SSL handshake has read 1372 bytes and written 404 bytes
Verification error: self-signed certificate
---
New, TLSv1.3, Cipher is TLS_AES_256_GCM_SHA384
Server public key is 2048 bit
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
Early data was not sent
Verify return code: 18 (self-signed certificate)
---
---
Post-Handshake New Session Ticket arrived:
SSL-Session:
    Protocol  : TLSv1.3
    Cipher    : TLS_AES_256_GCM_SHA384
    Session-ID: A61F4509B5496144321767C28A7ED025FF2F70DBAC3ECCADD199B03E3F24F69F
    Session-ID-ctx: 
    Resumption PSK: 67B84FCD31C5A0B39561BE8847E57CF09EC79CA404E2916B0F1C365D988F32FF214CC5FA2BB17DE2D2F89D04A3E60502
    PSK identity: None
    PSK identity hint: None
    SRP username: None
    TLS session ticket lifetime hint: 7200 (seconds)
    TLS session ticket:
    0000 - 21 7a dd b9 e6 7b b6 fb-ef 11 59 bc e0 55 36 99   !z...{....Y..U6.
    0010 - 49 c6 28 6b b1 84 07 d0-b9 d2 96 1b 5e 7d 59 41   I.(k........^}YA
    0020 - c7 8d 25 fd 3a ed 88 29-22 3b 6d 0e c4 71 ed 43   ..%.:..)";m..q.C
    0030 - d0 74 df d2 c2 1f c0 5f-f4 bf 60 f4 69 cb e3 5d   .t....._..`.i..]
    0040 - cc 7b 17 06 98 31 6b 3e-cc 8e b8 c7 a1 9b 9e d4   .{...1k>........
    0050 - 23 5f d5 e8 0d 47 82 2d-c5 ed b1 86 aa e1 2b b2   #_...G.-......+.
    0060 - 44 ee 4a 4c 1c 94 be 34-be fe ea 46 19 b1 c6 4f   D.JL...4...F...O
    0070 - 2d 01 a3 c6 1f 39 02 0b-18 8f f5 d8 9f 82 2c d1   -....9........,.
    0080 - 6b 16 52 e3 f6 51 f2 7d-47 d4 62 40 99 46 5e 69   k.R..Q.}G.b@.F^i
    0090 - 91 14 b6 1c 3c 49 74 df-48 71 c4 c6 ec a0 d3 b1   ....<It.Hq......
    00a0 - 4b ed 64 67 5f 6d cf 0e-a6 0a 67 73 8c fc 4e 38   K.dg_m....gs..N8
    00b0 - 7d b0 b8 95 88 0d 25 b9-52 c2 e3 12 b6 20 c5 72   }.....%.R.... .r
    00c0 - 07 71 26 80 e1 cc 0b 8c-e2 31 26 db 68 e8 91 8a   .q&......1&.h...
    00d0 - 89 4f 53 66 9e 88 fe fa-0c 6f e3 bd a7 54 cb 2d   .OSf.....o...T.-

    Start Time: 1713942967
    Timeout   : 7200 (sec)
    Verify return code: 18 (self-signed certificate)
    Extended master secret: no
    Max Early Data: 0
---
read R BLOCK
---
Post-Handshake New Session Ticket arrived:
SSL-Session:
    Protocol  : TLSv1.3
    Cipher    : TLS_AES_256_GCM_SHA384
    Session-ID: AEF8ABCC174B3B33FE937742B8D0C9579B9A8BEEE84359137B924BFCC06CBE2E
    Session-ID-ctx: 
    Resumption PSK: A3A7047434102076B74DB9998A589F071F18BFA70EB59E4F94167BFDCB75D303BBE5CAE7FB05EBB1F021456F2230421C
    PSK identity: None
    PSK identity hint: None
    SRP username: None
    TLS session ticket lifetime hint: 7200 (seconds)
    TLS session ticket:
    0000 - 21 7a dd b9 e6 7b b6 fb-ef 11 59 bc e0 55 36 99   !z...{....Y..U6.
    0010 - 19 64 61 b0 7a 8f a0 fb-3d 7d fa 61 13 82 4a eb   .da.z...=}.a..J.
    0020 - 64 17 dc e9 03 99 3b c1-d8 08 e4 74 1e 9f 62 a1   d.....;....t..b.
    0030 - 4f 5a e5 11 c5 ca 95 70-b9 b5 22 8a e9 cd 51 e7   OZ.....p.."...Q.
    0040 - 66 47 b3 75 6d ee 2b 3c-72 b2 93 23 9c 1d 08 56   fG.um.+<r..#...V
    0050 - 97 ca d8 95 11 c2 3d 5c-59 d8 de eb e1 4c 96 33   ......=\Y....L.3
    0060 - 7b d6 1a 85 fe cd 7f 93-ca ed c2 aa a7 08 fc 6a   {..............j
    0070 - bf 72 e0 bd dd 9d 6c fd-30 a1 a1 70 a7 3b 4f d2   .r....l.0..p.;O.
    0080 - 33 10 63 1a 34 b3 76 b3-0c 12 c5 36 70 ed 71 e0   3.c.4.v....6p.q.
    0090 - b0 8f 15 29 04 e4 49 19-75 e1 fb 1f be 31 2b 95   ...)..I.u....1+.
    00a0 - 4d 39 cb 79 de b7 21 4b-09 f1 02 be 14 c9 b6 50   M9.y..!K.......P
    00b0 - 74 98 1b 18 92 f9 dd 2b-92 73 8b 0e 05 f6 08 6b   t......+.s.....k
    00c0 - a0 02 71 92 c9 5c 3a 10-0b 6a ac 7d 88 16 14 ea   ..q..\:..j.}....
    00d0 - 1e d9 30 a8 52 ee 3b 44-6e 80 0d c2 5b ce 10 ab   ..0.R.;Dn...[...

    Start Time: 1713942967
    Timeout   : 7200 (sec)
    Verify return code: 18 (self-signed certificate)
    Extended master secret: no
    Max Early Data: 0
---
read R BLOCK
+OK Dovecot (Ubuntu) ready.
USER alexlai
+OK
PASS alex1765
+OK Logged in.
LIST
+OK 0 messages:
.
QUIT
DONE

Configure Dovecot: By default, Dovecot's configuration files are located in /etc/dovecot/. You may need to configure Dovecot to suit your specific requirements. The main configuration file is dovecot.conf, and additional configuration files can be found in the conf.d/ directory. Test Dovecot: You can test Dovecot by connecting to it using an email client like Thunderbird or using Telnet for basic testing. For example, to test the IMAP connection using Telnet: bash Copy code telnet localhost 143 This connects to the local IMAP server on port 143. If the connection is successful, you'll see a Dovecot greeting message.

Remember to adjust your firewall settings if necessary to allow traffic on the IMAP and POP3 ports (143 and 110 by default).

That's it! You've now installed Dovecot on your Ubuntu system.

User how to use let's encrypt with Dovecot ChatGPT To use Let's Encrypt SSL/TLS certificates with Dovecot, you can follow these general steps:

Install Certbot: Certbot is a tool provided by Let's Encrypt to obtain SSL certificates. You can install it on Ubuntu using the following command: bash Copy code sudo apt install certbot Obtain SSL Certificate: Once Certbot is installed, you can obtain an SSL certificate for your domain. Assuming your domain is example.com, you can use the following command: bash Copy code sudo certbot certonly --standalone -d example.com This command will prompt you to agree to the terms of service and will then automatically obtain and install the SSL certificate for your domain.

Configure Dovecot to Use SSL: Next, you need to configure Dovecot to use the SSL certificate. You'll typically do this in the Dovecot configuration file (/etc/dovecot/dovecot.conf). Open the Dovecot configuration file in a text editor:

bash Copy code sudo nano /etc/dovecot/dovecot.conf Find the section that configures SSL settings, it may look something like this:

typescript Copy code ssl_cert = </etc/ssl/certs/dovecot.pem ssl_key = </etc/ssl/private/dovecot.pem Replace the paths with the paths to the SSL certificate and private key obtained from Let's Encrypt:

javascript Copy code ssl_cert = </etc/letsencrypt/live/example.com/fullchain.pem ssl_key = </etc/letsencrypt/live/example.com/privkey.pem Save the changes and exit the text editor.

Restart Dovecot: After updating the configuration, you need to restart the Dovecot service for the changes to take effect: bash Copy code sudo systemctl restart dovecot Automate Certificate Renewal: SSL certificates obtained from Let's Encrypt are typically valid for 90 days. To ensure uninterrupted service, it's important to set up automatic renewal of the certificates. You can do this by adding a cron job to run the Certbot renew command periodically. Certbot will automatically renew certificates that are close to expiration.

bash Copy code sudo crontab -e Add the following line to the crontab file to run the renewal check daily:

bash Copy code 0 0 * * * certbot renew --quiet Save the changes and exit the text editor.

That's it! You've now configured Dovecot to use Let's Encrypt SSL/TLS certificates, and automatic renewal is set up to keep your certificates valid.