Without wanting to suggest anything is wrong with MP's replying to letters from constituents, it seems incredible that Labour MP Shahid Malik should receive so many letters from his constituents that he should spend £21,000 on postage alone.
Working on the basis that it is roughly 25p for postage per letter, that means he sent out 84,000 letters last year. This means he could have sent a letter to each of the households in his constituency nearly three times.
This also works out at 1,700 letters a week or 350 a day. However many staff must he employ in order for them to write that many individual letters a day.
I think I could only write that many if I was sending out mass mailings, and I am sure he wouldn't be doing that, would he.