make sure in the settings under the email account in question you have it set to download the entire message instead of the first line or first 25K of the message, etc.
next , remove the spamarrest thingy if the above is not helpful.
remove the account and re add it.
verify you are using the proper pop (or imap) and smtp servers for the account in question.
i have several email accounts (imap) and I have no issues.