beta通道中仍然没有64位版，遗憾
更新内容2L

New
Allow editing of From when composing a message.
New
AB quick search and contacts side bar will search nicknames
New
Allow copying of Name and Address from an email displayed from header menu.
New
Allow printing of individual contacts from context menu
New
Mail.ru supports OAuth authentication.
New
Implement option to always use HTML formatting to prevent unexpected format loss when converting messages to plain text.
New
Return/Enter in composer will now insert a new paragraph by default (shift-Enter will insert a line break
NEW
Add dropdown in compose to allow specific setting of font size
Fixed: New emails into a mailbox did not adhere to sort order by received
Fixed: Box.com attachments failed to upload
Fixed: Grouped By view sort direction change was broken, plus enabled custom column grouping
Fixed: When sending e-mail which was composed using Chinese, Japanese or Korean characters, unwanted extra spaces were inserted within the text
Fixed: Drag and drop of multiple attachments failed to OS file folder
Known Issues
Unresolved：
Linux builds for version 45.0b1 use GTK3, but are not offered for update because GTK2 will be used in future Thunderbird 45 versions. Fixed in 45.0b2.

新增功能：
允许在进行构建的消息中进行编辑
AB快速搜索和联络侧边栏可以搜索昵称
允许从头菜单已经显示的Email中复制姓名和电子邮件地址
允许从上下文菜单中打印单个联系人
Mail.ru支持OAuth认认证
实现了一个选项，始终使用HTML格式来格式化在转换消息格式到纯文本时遇到的意外错误
Return/Enter键将默认插入一个新的段落（Shift+Enter将插入一个软回车）
添加了一个下拉菜单以在便携消息时选择特定的字号
修复的问题：
修正：新的电子邮件存入邮件夹时没有随着接收到的顺序存入的问题
修正：Box.com附件上传失败的问题
修正：分组的视图排序方向变化出现问题，以及启用自定义列分组
修正：在发送电子邮件时，使用中文，日文或韩国文字，不需要额外的空格内插入文本
修正：将多个附件拖放到操作系统文件夹失败的问题
已知问题
未解决
Linux的45.0b1版本使用gtk3构建版本，但不提供更新。未来的TB45版本将使用GTK2构建。该问题将在45b2中修复。