Mail draft for company rules follow - to wear a company T-shirt every 2nd Saturday of the month

Hello all, I newly joined in construction co. and their rule is to wear a company T-shirt every 2nd Saturday of the month. but some employees not following the rule. I want to draft an email to employees about following company rules. as I said I'm new in this company, and want softly and diplomatic mail draft for following rules by employees.

Regards,
Trupti

It is just an email, don't overthink these things.

Tell them what you have told us. Simple as that. Don't complicate the issue.

Trying to write things in flowery language doesn't work and is open to interpretation. Tell them the rule, explain the consequences for not complying, and remind them to talk to their manager if there is a reason they cannot wear the shirt.