“If the courier will still deliver your parcel, we ask you to refuse it.”

Question

Context: Parcel shipping. A parcel has been lost and the client has been refunded. However, in case the parcel would be found and delivered, the client should refuse it.

Phrase: “If the courier will still deliver your parcel, we ask you to refuse it.” or “If the courier still delivers your parcel, we ask you to refuse it”

Which one is correct?

Answer 1

I woud suggest
"If the courier delivers the parcel after you have accepted a refund, please refuse it, and it will be returned to us."

You could say "still delivers", but I think it's clearer as above.
The form with "will still deliver" doesn't work, because it sounds as if it has to do with the willingness of the courier.

Answer 2

Will, like all modal auxiliary verbs, has two kinds of meaning.

One kind of modal meaning is called Epistemic -- it has to do with logic and the speaker's conclusions about possibility, probability, and necessity. Examples of epistemic modal uses include:

• This must/must not be the place he told us about. ('it's likely/not likely to be')
• This can't be the place he told us about. ('it's not likely to be')
• He should be home by now, don't you think? ('he's likely to be')
• He must be home by now; go ahead and call. ('he's likely to be')
• He won't be home yet; don't call till 6. ('he's not likely to be')
• He'll be home by 6; you can call then. ('he's likely to be')
  (The epistemic use of will is sometimes called "the future tense",
  but in fact all modals can refer to the future in their epistemic sense.)

The other kind of modal use is called Deontic -- it has to do with social obligations and permissions. Examples of Deontic modal uses include:

• She can/can't go to the dance this week. ('she is/isn't permitted to')
• You must stay 6 feet apart. ('you are obliged to')
• You should stay 6 feet apart. ('you are obliged to')
• You must not say anything ('you are obliged not to')
• You need not say anything. ('you are not obliged to')

Will has an unusual restriction on its deontic sense; it means 'be willing to' (from the same root), and it is restricted to negatives and hypothetical clauses. In the following, will and won't mean 'be willing to' or 'be unwilling to':

• He won't unlock the door; I've tried everything but he refuses.
• If he won't unlock it, we'll have to call the police.
• But if he will unlock it, there'll be no problem.

Since will always has this sense in an if-clause, students are sometimes taught that "the future tense is incorrect after if", or some such similar nonsense. There is no future tense in English -- present and past is it. And will can certainly occur after if; it's just that will has a special meaning when it does.

So the first sentence means 'if the courier is still willing to deliver', while the second one doesn't refer to willingness, but simply to future possibilities.