1. An information processing apparatus for obtaining a plurality of messages and extracting one or more messages from the plurality of messages, the information processing apparatus comprising: a memory configured to store first filter information specifying formats of messages and second filter information specifying weights for words or phrases; and a processor configured to perform a procedure including: selecting, from the plurality of messages, messages matching the formats specified by the first filter information as messages to be extracted; calculating an importance level of each message that has not been selected based on the first filter information, based on words or phrases included in said each message and the second filter information; and selecting messages to be extracted, according to calculated importance levels from messages that have not been selected based on the first filter information.