Mail shows blank body for messages

Question

sometimes mail refuses to show the bodies of certain messages for me.
typical sequence:
1 start mail.app
2 use it for a while (working normally)
3 notice that certain message bodies appear "blank"
when #3 occurs, i select a message in list view and the preview window (where you usually see the contents or body of the message) is totally blank. once this happens for one message, it seems to also happen for many of my other messages, too. that is, if i try to select a different message (even one whose body i was just reading a few seconds ago), it now shows up with a blank preview window. i also try double-clicking to open the message in it's own window - the body part of the window is blank. i try printing the message - the body part comes out blank.
if i quit mail and restart and come back and view the same message, i can see the body ok (for a while, at least - until the problem eventually happens again). thus, this feels to me more like an issue of some kind of memory leak or some system resource being exhausted rather than some corruption of my mail files or preferences.
some things i have noticed:
- if i go to view->message->plain text alternative, i can sometimes see a plain text view of the message. this works for certain messages. for other messages (which seemingly don't have plain text alternatives) i can't do this. and for certain messages (seemingly those which were sent as raw text), i can see their bodies without doing this. the pattern seems to be that i can view text-only messages or plaintext-views of messages which provide them but i can not view them as formatted text.
- i can always view the raw text of messages.
- once this problem occurs, if i try to compose a new mail message, the window pops up and looks normal except i can not select the body part of the message. that is, hitting tab which usually works to move through the header fields and puts the cursor in the body field, simply fails to move the cursor to the body. clicking directly on the body just causes the cursor to disappear. so it is impossible to compose a new message.
- once the problem occurs in a particular instantiation of mail.app, it never seems to go away. the fix i know of is to quit mail. that always seems to make it go away, though only temporarily.
i'm wondering if anyone has experienced this problem and may have any hints as to the root cause. i should warn that i am a a bit skeptical of claims of simple fixes such as simply deleting and rebuilding the envelope database, deleting preferences, etc., because i already know that the problem is tricky in that it goes away with every restart of mail.app anyway which can lead to false reinforcement of various theories.

Answer 1

Mulder wrote:
That's nonsense; the problem doesn't go away, it merely doesn't manifest immediately, which tells us it's still there. More often than not, there is a simple fix for an underlying issue; of course, if you'd prefer something much more complicated, I'm sure we can give you all those machinations.
sorry - i should have been more precise and said the symptoms go away after restarting mail. i said what i said because my experience is that this type of scenario sometimes tends to lead people to conclude falsely that they have identified a solution when in fact they have not. this is why, for example, "reset pram" always was claimed a solution to dozens of problems for which it had absolutely no connection. it was because merely restarting the machine (an essential precursor to resetting pram) made symptoms go away in many cases.
as to your specific point, i have rebuilt envelope index in the recent past and i'm still having the problem. i can't say for sure that it is not the case that something messed up the file in the past and has now messed it up again, so i will give it a try.
thanks.