Hi,
https://gitlab.com/muttmua/mutt/-/work_items/453 notes that some
people consider the local hostname to be private information, and
requests that Message-ID not contain the local hostname.
Some MUAs use the sending domain, which I don't really like. It's
fine for your own domain, but many people use gmail addresses.
Message-ID:
<[email protected]>
needs a LOT of entropy in the localpart in order to be safely
unique.
However, the sending domain isn't conveniently available at that
spot in the code.
Another alternative is to use a domain from the MUA, I like that
better, so I suggest the below as a solution for #453. The
repeated %r gives 120 bits of entropy while keeping the message-id
fairly short.
I removed the time. I don't see the value of including the time,
it's bulky and reminds me of the passage on Knuth vol 2 where he
"attempted to create a fantastically good", etc. The best
protection against clashing message-ids is IMO to spend the entire
length on high-entropy randomness and avoid low-entropy components
like the time. If we can increase the length, it's IMO better to
spend the extra length on more entropy.
Arnt
diff --git a/init.h b/init.h
index af684866..ae3760f9 100644
--- a/init.h
+++ b/init.h
@@ -2202,7 +2202,7 @@ struct option_t MuttVars[] = {
{ "msg_format", DT_SYN, R_NONE, {.p="message_format"}, {.p=0} },
/*
*/
- { "message_id_format", DT_STR, R_NONE, {.p=&MessageIdFormat}, {.p="<%z@%f>"}
},
+ { "message_id_format", DT_STR, R_NONE, {.p=&MessageIdFormat},
{.p="<%r%r%r%[email protected]>"} },
/*
** .pp
** This variable describes the format of the Message-ID generated
