It is so great to hear from you again.

　　It is a great pleasure for me to …

　　With great delight I learned that …

　　I must apologize for not writing to you sooner.

　　建议：

　　In my experience, it seems that _______ would make sense in your situation

　　In my opinion, it would be wise for you to take the following actions:

　　感谢：

　　I truly appreciate your kindness.

　　Thank you from the bottom of my heart for...

　　道歉：

　　I apologize most sincerely for...

　　I am so sorry to have put you through so much trouble...

　　邀请：

　　We would be honored to have you there with us...

　　I will cover all the expense involved.

　　抱怨：

　　I very much regret to have to inform you that...

　　We will appreciate your willingness to make up for the loss
　　I hope that the above situation will be improved as soon as possible

　　咨询：

　　I would like to request some information about...

　　Should I need to send further materials, please let me know.

　　求职：

　　In anwser to your advertisement I wish to apply for a post as … in your office.

　　I hope I may be granted an interview…