Hello.
How are you?

It's already become September.

-It's already September. / We are now in September.

As you also know, the scheduled deadline is the end of September, so I am writing an e-mail to make sure your situation and schedule are okay.

-As you  may already know, the scheduled deadline is in the end of September. I am writing to get an update of your situation and schedule. Is every everything okay so far?

Please kindly let us know if you need any help or adjustment to the schedule.

Don't hesistate to let usk now if you need any help.

We wish you remember that we are always waiting to help you.

-Rest assured that we are always here to help and guide you all the way.

(We would appreciate it if you could simply let us know your progress.)
I look forward to hearing from you.

-( We would appreciate for any update on your end....)

Thank you.


(is this mail polite enough? .. I am trying not to give them any pressure...; )