E-mail language

Teaching business English makes me develop my vocabulary as each area has its own technical terms. It's great fun, but it's also challenging!
A lot of the communication in the business world nowadays is through email and that's where many doubts come up.
Because of this I decided to list here some expressions you can use while writing an email:

To start:
Dear Mr./ Mrs./ Ms...
Hello ...
Good morning/ afternoon/ evening...

To refer to previous contact:
Following our meeting (phone call), I'm writing to...
Sorry for taking so long to answer.

To say thank you:
Thanks for replying so quicly...
I appreciate your help on...

To refer to an attachment:
Please find attached
I'm attaching

To ask for a reply:
I look foward to hearing from you
Please get back to me ASAP

To finish:
Best Regards
Regards
Sincerely

 Activity-Complete the folowing e-mail with the expressions listed above:

__________ Mr. Stevens,

_________________________________, I'm writing to inform you that the order you placed won't arrive on time. I apologize for the inconvenience, but we had problems with our supplier.
_________________ a bonus discount for you next purchase.

_______________
Mary Richards

You can leave your answer on the comments! I hope this can be helpful!