I received a mail from a colleague saying that he had noticed that I am a delinquent for not filing something in time. I found it offensive. Is it alright to use the delinquent for someone who has missed doing a particular task? Is it polite and professional to do so in formal communication?
You are misinterpreting the usage.
- failing in or neglectful of a duty or obligation; guilty of a misdeed or offense.
- (of an account, tax, debt, etc.) past due; overdue.
2: being overdue in payment
Your colleague is not calling you a troublemaker or law breaker. They are saying that the item you were supposed to file is late (definition 2). When used to mean past due or late, the word is not offensive or rude.
It is very common to say something like "Your time sheet is delinquent, please submit it immediately." Or if you don't pay a credit card or loan payment on time, then that payment is considered delinquent. It is quite common in professional settings and your colleague is not insulting you.