While writing any kind of emails (ex business emails). I have seen many people, when informing about something to the other person, starting their email with the following 2 sentences (one or the other):
"I would like to inform you that the document you asked for has been completed."
"This is to inform you that the document you asked for has been completed."
Which sentence looks more formal and polite to the recipient?
The first is more polite while the second is more impersonal and better suited to a corporate or institutional setting where the recipient might not have a relationship with the writer.
Both are however too wordy; the recipient knows you're informing her by the fact that you're sending her a message. 'Asked for' is also too colloquial for a business or academic setting. I'd use 'requested'.
Also, the word 'completed' is ambiguous and not idiomatic (it could mean that it's been scanned but not made available for download, for instance). I would suggest instead:
"The document you requested is ready for pickup."
or if it is to be downloaded,
"The document you requested is available for download at [URL]."
or if you're sending this message with a PDF or other electronic copy of the document,
"Please find enclosed XXXXXX, per your request."
I think, the first sentence is better for the formal letters. But the second one is could be great as well. Maybe just for me, but I think these are interchangeable, and you can use any of them.
