1、may i have your reply by april 1, if possible?
如果可能，我可否在4月1日前收到您的答复?
2、if you wish, we would be happy to…
如果你希望，我们很乐意…
3、please let me know if there’s anything i can do to help.
请让我知道任何我可以帮得上忙的地方…
4、if there’s anything else i can do for you on/regarding this matter, please feel free to contact me at any time.
对于这件事，如果还有任何我能帮得上忙的地方，请不要客气，随时与我联络…
5、if you want additional recommendation on this, please let us know and we can try to see if this is possible.
如果关于此事你需要额外的建议，请让我们知道，我们会尝试看看是否可能…