Dovecot upgrade from 2.3 to 2.4

•  see link for detail guideline, Archlinux provide dovecot23 as alternative
• add two new configuration, see link
• dovecot_config_version = 2.4.2
• dovecot_storage_version = 2.4.2
• delete empy dict

#dict {
#quota = mysql:/etc/dovecot/dovecot-dict-sql.conf.ext
#expire = sqlite:/etc/dovecot/dovecot-dict-sql.conf.ext
#}

• change "disable_plaintext_auth = yes" to "auth_allow_cleartext = no", see link
• rename userdb and passdb. 
• passdb authenticated the user. 
• userdb lookup then retrieves post-login information specific to the authenticated user

userdb passwd {
          #driver = passwd
}
passdb pam {
          #driver = pam
          passdb_driver=pam
}

• update mail location, see example on link.

#mail_location = mbox:~/mail:INBOX=/var/mail/%u
#mail_location = mbox:~/mail:INBOX=/var/mail/%{user}

mail_driver = mbox
mail_path = ~/mail
mail_inbox_path = /var/mail/%{user}

• update ssl, see linklink.

#ssl_cert = </etc/letsencrypt/live/hongy19.net/fullchain.pem
#ssl_key =  </etc/letsencrypt/live/hongy19.net/privkey.pem
#ssl_dh =   </etc/dovecot/dh.pem
ssl_server_cert_file = /etc/letsencrypt/live/hongy19.net/fullchain.pem
ssl_server_key_file = /etc/letsencrypt/live/hongy19.net/privkey.pem
ssl_server_dh_file = /etc/dovecot/dh.pem

• rename "service_count = 1" to "service_restart_request_count = 1", see link.

/var/permission

 

from link, /var/mail should have correct permissions 2775 root:mail

The first digit "2" represents the setgid (Set Group ID) special permission:

• 2 = setgid bit enabled
• When set on a directory, new files created within inherit the directory's group ownership
• This ensures all mail files created in /var/mail automatically belong to the mail group

The s represents the setgid bit. It appears in the group execute position:

• Normal group permissions: rwx (read, write, execute)
• With setgid: rws (read, write, setgid)
• With setgid but no execute: rwS (capital S)

pdflatex + ctex support Chinese font

•  Xelatex could support Chinese with ctex + Truetype/OpenType font. you could search web for detail.
• latex could support Chinese with ctex + tfm/pk font.
• pdflatex need type1 font, so tfm/pk and Truetype/OpenType font doesn't work. But there are three ways to support Chinese for pdflatex
• ctex + simsum.ttc
• \documentclass[fontset=windows]{ctexart} 
• zhmetrics provide tfm file for simsun.
• zhmetrics provide mapping file to map tfm back to simsun.ttf (Truetype), but not for other Chinese ttf font,  see /usr/share/texmf-dist/tex/generic/zhmetrics/zhwinfonts.tex
• it embedded Trutype font into pdf.

• ctex + CJKutf8 + gbsn. 
• it embedded type1 font into pdf, you could use "pdffonts" to check.

\documentclass[fontset=none]{ctexart}

\usepackage{CJKutf8}
\begin{document}
\begin{CJK*}{UTF8}{gbsn}
你好，世界！
\end{CJK*}
\end{document}

• CJK + gbsn

\documentclass{article}
\usepackage{CJK}
\begin{document}
\begin{CJK}{UTF8}{gbsn}
这是一个CJKutf8的例子，使用的字体是gbsn。
\end{CJK}
\end{document}