For the business communication by email with cellular phones, it has an important weak point. That is to hard to tell to be utterance speed and the pitch of sounds involved in the sentences, because it communicate by letters only. Emoticons are often used to make up for this weak point. This paper describes techniques to predict emotions of sentences in Japanese emails and give an emoticon to end of a sentence automatically. This is achieved by learning information of emotions with emoticons used and analyzing the text of email with cellular phone by collecting and analyzing our corpus of emails. We also examined consistency evaluation with real email sentences input by cellular phones and emoticons automatically generated by this technique. We could get correct answer rate of 87.7%.