collect email addresses

why doesnt em client collect email addresses of people I send mail to?

Hi Khizer, eM Client does keep track of the recipients you use in eM Client, when typing an address into the to field all recently fetched addresses should show up while typing in the address.
Unless you have this option disabled in Tools > Settings > Mail > Compose > “Store composed mail recipients for suggestion”.
You can also review the fetched addresses by using the “Show recipients” button in that settings window.

Hope this helps,
Paul.