1.Thank you for your e-mail.

感谢你的来信。

Thank you for contacting the Customer Assistance Center.

感谢您联系客户援助中心。

Thank you for your e-mail on May 11th.

感谢您5月11日的来信。

I appreciate your kind reply to my question.

感谢您耐心回答我的问题。

2.It's good to hear from you.

收到您的消息真好。

It's always great from you.

收到您的消息总是很高兴。

It's wonderful to hear from you. How have you been?

收到您的消息真是太棒了。您最近过得怎么样？