So as you ask for information from experts via the mailing list, consider that this will be your only chance. Ask your students to help. Learning to construct effective questions is an important Information Age skill. When writing your request for information, make it short. Once again, the people to whom you are sending the message are busy, and do not have time to read a lengthy letter.
People are more likely to read many short paragraphs than a few long paragraphs.
Do not write a lengthy introduction. Explain very briefly what your class is doing so that you don't waste the time of a busy person. Include a signature at the bottom of your message. If you are soliciting information from a mailing list used by K-12 educators, then promise something in return. If you are developing a new unit on butterflies, then offer to send your teacher friends a copy of the unit.