abscences - no stamps in passport

[okokok]

Sorry if this has been already asked:

I am about to apply for ILR later this year (switching from Tier 2 General), and face the problem of providing information on my abscences in the first three years: I changed my employment two years ago, and with this switch my previous email account was disactivated. Neither UK nor my country press stamps in the passports on your leaving/arival. I'm sure I'm not the first finding herself in such position -- and any recommendation would be very appreciated.