我的解释信贴一下，供有用者参考，真正感觉到了论坛的温暖
Dear officer
I am very sorry for that I failed to submit the following information and documents for skilled migration as requested by email within 45 days. Below are the special reasons for the delay. I hope you can reconsider delayed processing to the information submitted.
On November 6, 2012, I gave birth to my second child. Due to health reasons, I asked for a 4-month vacation from my company. The email that I used for immigration application belongs to the company that I serve. As our company is very strict with information security requirements and the email can be logged in only on the intranet of the company. Therefore, any letter received by the company’s email can not be accessed at home during my vacation. The email on Dec 6 2012 asking for medical examination and submission of following information was missed by me. When I read it on Feb. 4, 2013, it has been a 45-day delay. Therefore, I could not complete medical examination and submit the information required within the time required.
Again, I deeply apologize for my mistakes. I hope that you can consider my special circumstances and give extension for information submission.
Thank you for your attention to this mattter.
Name： XXXXXX File number: BXXXXX
