If your subject is a question that pertains to you and not to most of the group, you may want to suggest that answers be sent directly to you. You might later provide the group with a summary of the answers. If you want to call attention to an article or information you have found, it is preferable to have a hyperlink or a reference to the source and provide instructions on how to read it or obtain a copy. You may send an attachment to an individual member if they are interested and capable of receiving it. Even a small photo takes a lot of space.
Email goes to everyone on the list.
All lower case is difficult to read and follow. Bad spelling and bad grammar are difficult to read and understand. In many cases, an Email reply directly back to the individual member would be most appropriate. Use your best judgment. When responding to a member's posting via the list, keep your reply brief and to the point, but as complete as possible.