Q: Is it permissible for me to appoint someone to distribute my zakat? If so, must they know it is zakat?
A: Yes. It is permissible to appoint a trustworthy mature Muslim to distribute your zakat. If it will be distributed immediately, it only requires your intention and therefore your trustee does not need to know it is zakat.
If it will be distrubuted at a later date, it requires your intention when giving it to your trustee and their intention when distributing it and therefore they must be aware it is zakat.
Source: Hidayat al-Raghib