In Business communication^x, Tenses^x

Hi,This is Babu.I am having doubts while using past tense in conversation.by using could,wolud,had, had been like that.

Both are fine in both cases, Paperkite, and the members of each pair carry essentially the same message. If this is a business communication, you might want to use the first form of the second case, changing 'thanks' to 'thank you'.