Absence letter email or original paper copy from previous employer

Hi folks,
I hope you are all doing well.
I have a query regarding absence letter from previous employer.
I had requested absence letter from my previous employer while I was on notice period. However, I did not get it on my last day. Now I need to chance via email to follow up.
My question :
1) Is it acceptable to have the signed scanned copy of the letter or do I need to request a postal copy of the letter from the previous employer.
2) As I have already left the employment, chances are slim that I get the absence letter from my previous employer. Will there will an issue for my ILR if I do not obtain this letter (as it is always difficult to chase when you left the employer) (absences not more than 20 days in 3 years period of employment)?

I am concerned.

Thanks very much for helping with my questions