If you can offer refuge to a bun needing a home, make the offer privately. If you want to arrange a regional meeting, announce your intent on the list, but work out the details in private mail. You can assume that we've already read the post you are responding to. Because of the high volume we may not always remember everything that was said before. Not only is it ugly and hard to read, but it is usually interpreted as shouting.
Some systems actually send each paragraph as one long line.
AOL is especially bad in this respect. These files are HUGE when encoded and will sometimes break some folks mail-servers. The encoded attachments are also extremely time-consuming to download and a true pain in the neck to people getting the digest. If you have a file you think might be of interest to other folks on PB, post an announcement and arrrange to send the file directly to those who express an interest. This will simply provoke an on-list response and encourage others to join the fray.