Is it possible to associate a new unknown contact to an existing account?

Is it possible to associate a new unknown contact to an existing account?

I would like to know how to be able to receive an email, adding it directly to an existing account?

For example:
a collague(Tim from BCorp) from my contact (Tom from BCorp) writes to me and I would like to find it filed under the related account BCorp, taking into consideration the fact that Tim is not yet inserted in the CRM

Which steps should I accomplish?

Thanks.