sg 8 edge how to access old emails

There seems to be no setting that addresses change to the period for which access to emails can be provided.

By inference (i.e. observation) the default seems to be 30 days or 1 calendar month.

Even this inferred period is not stated anywhere (that I can see)
in settings including email or app settings.

Which email program?

Gmail for Android Gmail, Settings, select email account, scroll down to days of email to sync. What does it say?