Learn English – How to ask, “Why did you send me this link?” in a polite way

Irrespective of whether most people in a certain region find it polite or not, if you are dealing with a customer and one you've probably not interacted with before, your best bet - more so from a business perspective, is to use safer alternatives, such as beg your pardon?.

Some might say I'm not answering the question and going tangential, but I think perception of rudeness can be subjective and therefore not just within in the realm of grammatical correctness.

I guess you were told so, because the first one implies that the question will be asked, no matter what.

In the second case, one asks only if he/she may ask something. In this case, the decision whether to listen to the question or not is in in the hands of the person from whom it was asked. It makes the act of asking the question more polite and less invasive for the receiver.

Even so, the first one is pretty acceptable too. I would say it depends to whom it is said and in what context. In a formal conversation or when the receiver is a professor for ex. the second one is more suitable. For informal, the first one works.