bugs of service desk

Summary

bug1

如果用户发送的邮件信体包含中文，极狐 GitLab 无法正常显示中文，如下： 用户邮件： GitLab issue 解析邮件：

bug2

如果项目用户回复的邮件中使用了 markdown 语法的内容或者其他语言的代码，例如html，那么用户接受到的邮件将无法正常显示 comments 内容。

bug3

用户新发送或者转发的邮件存在一定概率被 rejected，此问题目前没有探索到规律。目前从测试看出现此问题频率略高。在服务器配置没有任何变更调整的情况下，会间歇性出现如下问题。此处可以非常确定收件地址和项目 service desk 地址是一样的，暂未找到后台相关日志。

Steps to reproduce

Example Project

What is the current bug behavior?

What is the expected correct behavior?

Relevant logs and/or screenshots

Output of checks

Results of GitLab environment info

Expand for output related to GitLab environment info

(For installations with omnibus-gitlab package run and paste the output of:
`sudo gitlab-rake gitlab:env:info`)

(For installations from source run and paste the output of:
`sudo -u git -H bundle exec rake gitlab:env:info RAILS_ENV=production`)

Results of GitLab application Check

Expand for output related to the GitLab application check

(For installations with omnibus-gitlab package run and paste the output of:
sudo gitlab-rake gitlab:check SANITIZE=true)
(For installations from source run and paste the output of:
sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production SANITIZE=true)
(we will only investigate if the tests are passing)

Possible fixes