Outlook uses a left to right search engine technique when trying to match unknown addresses. Depending on whether they have sent an email to both or not would make a difference. Once you have sent to both addresses it will give you a list showing both addresses from their suggested contacts list. searching the global address list will bring up all entries containing that partial entry as well. Seems to search by default in most cases as you are asking, but I can't confirm without purging my suggested contacts as to whether its the default when typing in an unknown address from the middle. It searches both name and email address in most cases or even the other fields to find matches.
There are two e-mail addresses:
When I use Thunderbird and write into TO field "name.surname", it finds both e-mail addresses.
Outlook on other hands finds only first one that starts with "name.". If users wish to find "department.", them must start their TO filed with "department.".
Is there a way in outlook to change how TO search works, to make it search in between the addresses and not just beginning?