email-check-extension by 北京安天网络安全技术有限公司

Required permissions:

• Exchange messages with programs other than Firefox
• Access browser tabs
• Access your data for mail.163.com
• Access your data for mail.126.com
• Access your data for wx.mail.qq.com
• Access your data for mail.antiy.cn
• Access your data for mail.yeah.net
• Access your data for qiye.aliyun.com

Data collection:

• The developer says this extension doesn't require data collection.