Teaching Email / Tone Across a Power Gap
Firm and cold are not the same thing.
Clarity about what must happen can coexist with obvious goodwill.
Firmness lives in the content: the deadline is this date, the requirement is this, the work needs to be submitted. Coldness lives in the framing: an absence of any acknowledgement that a person is receiving this, no recognition of circumstances, no offer of help, no sign that you would prefer a good outcome to a bad one. It is entirely possible to be immovable on the requirement and warm about the person, and that combination is the one that produces cooperation rather than defensiveness.
Coldness often creeps in through defensive writing. When you expect pushback, you write to protect yourself: passive constructions, references to policy in the abstract, formality that puts distance between you and the decision. The reader feels the armour and reads it as hostility or as bureaucratic indifference. Ironically the armoured message provokes exactly the escalation it was written to prevent, because a family that feels processed rather than spoken to will go looking for someone who will speak to them.
A useful test is whether your message contains a single sentence that could only have been written by a person who knows this particular student. One accurate, specific detail does more for tone than any number of pleasantries. It proves attention. And attention, not agreement, is what most families are actually checking for when they read something they do not like.