==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 3.3
- Deployed with iRedMail Easy or the downloadable installer? Yes
- Linux/BSD distribution name and version: CentOS7
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Web server (Apache or Nginx):Niginx
- Manage mail accounts with iRedAdmin-Pro?xiangct@
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
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我们希望更新到最新的版本，请问需要做什么？有没有操作文档参考？是否会导致邮件账号和数据的丢失？