diff --git a/docs/config.c b/docs/config.c
index 77d9232a8..c03b9bc93 100644
--- a/docs/config.c
+++ b/docs/config.c
@@ -1636,7 +1636,9 @@
 /*
 ** .pp
 ** When \fIset\fP, NeoMutt will skip the host name part of $$hostname variable
-** when adding the domain part to addresses.
+** when adding the domain part to addresses.  This variable does not
+** affect the generation of Message-IDs, and it will not lead to the
+** cut-off of first-level domains.
 */
 
 { "hidden_tags", DT_SLIST, "unread,draft,flagged,passed,replied,attachment,signed,encrypted" },
@@ -1753,7 +1755,8 @@
 ** .pp
 ** Specifies the fully-qualified hostname of the system NeoMutt is running on
 ** containing the host's name and the DNS domain it belongs to. It is used
-** as the domain part (after "@") for local email addresses.
+** as the domain part (after "@") for local email addresses as well as
+** Message-Id headers.
 ** .pp
 ** If not specified in a config file, then NeoMutt will try to determine the hostname itself.
 ** .pp
diff --git a/docs/manual.xml.head b/docs/manual.xml.head
index 0a42a6846..09e4d5266 100644
--- a/docs/manual.xml.head
+++ b/docs/manual.xml.head
@@ -19309,8 +19309,18 @@ set use_threads=threads sort=last-date sort_aux=date
       <sect2 id="security-leaks-mid">
         <title>Message-Id: headers</title>
         <para>
-          Since 2023-02-18 NeoMutt generates random Message-Id: headers, which
-          do not leak any information beyond their randomness.
+          Message-Id: headers contain a local part that is to be created in
+          a unique fashion. In order to do so, NeoMutt will <quote>leak</quote>
+          some information to the outside world when sending messages: the
+          generation of this header includes a step counter which is increased
+          (and rotated) with every message sent. Other parts include the date,
+          time, PID of NeoMutt, and <link linkend="hostname">$hostname</link>.
+          In a longer running NeoMutt session, others can
+          make assumptions about your mailing habits
+          depending on the number of messages sent. If this is not desired, the
+          header can be manually provided using
+          <link linkend="edit-headers">$edit_headers</link> (though not
+          recommended).
         </para>
       </sect2>
 
diff --git a/send/sendlib.c b/send/sendlib.c
index 849e50661..68ab3adab 100644
--- a/send/sendlib.c
+++ b/send/sendlib.c
@@ -726,42 +726,25 @@ const char *mutt_fqdn(bool may_hide_host, const struct ConfigSubset *sub)
 }
 
 /**
- * gen_msgid - Generate a random Message ID
+ * gen_msgid - Generate a unique Message ID
  * @retval ptr Message ID
  *
- * The length of the message id is chosen such that it is maximal and fits in
- * the recommended 78 character line length for the headers Message-ID:,
- * References:, and In-Reply-To:, this leads to 62 available characters
- * (excluding `@` and `>`).  Since we choose from 32 letters, we have 32^62
- * = 2^310 different message ids.
- *
- * Examples:
- * ```
- * Message-ID: <12345678901111111111222222222233333333334444444444@123456789011>
- * In-Reply-To: <12345678901111111111222222222233333333334444444444@123456789011>
- * References: <12345678901111111111222222222233333333334444444444@123456789011>
- * ```
- *
- * The distribution of the characters to left-of-@ and right-of-@ was arbitrary.
- * The choice was made to put more into the left-id and shorten the right-id to
- * slightly mimic a common length domain name.
- *
  * @note The caller should free the string
  */
-static char *gen_msgid(void)
+static char *gen_msgid(struct ConfigSubset *sub)
 {
-  const int ID_LEFT_LEN = 50;
-  const int ID_RIGHT_LEN = 12;
-  char rnd_id_left[ID_LEFT_LEN + 1];
-  char rnd_id_right[ID_RIGHT_LEN + 1];
   char buf[128] = { 0 };
+  char rndid[MUTT_RANDTAG_LEN + 1];
 
-  mutt_rand_base32(rnd_id_left, sizeof(rnd_id_left) - 1);
-  mutt_rand_base32(rnd_id_right, sizeof(rnd_id_right) - 1);
-  rnd_id_left[ID_LEFT_LEN] = 0;
-  rnd_id_right[ID_RIGHT_LEN] = 0;
+  mutt_rand_base32(rndid, sizeof(rndid) - 1);
+  rndid[MUTT_RANDTAG_LEN] = 0;
+  const char *fqdn = mutt_fqdn(false, sub);
+  if (!fqdn)
+    fqdn = NONULL(ShortHostname);
 
-  snprintf(buf, sizeof(buf), "<%s@%s>", rnd_id_left, rnd_id_right);
+  struct tm tm = mutt_date_gmtime(mutt_date_now());
+  snprintf(buf, sizeof(buf), "<%d%02d%02d%02d%02d%02d.%s@%s>", tm.tm_year + 1900,
+           tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec, rndid, fqdn);
   return mutt_str_dup(buf);
 }
 
@@ -799,7 +782,7 @@ void mutt_prepare_envelope(struct Envelope *env, bool final, struct ConfigSubset
     mutt_set_followup_to(env, sub);
 
     if (!env->message_id)
-      env->message_id = gen_msgid();
+      env->message_id = gen_msgid(sub);
   }
 
   /* Take care of 8-bit => 7-bit conversion. */
@@ -872,7 +855,7 @@ static int bounce_message(FILE *fp, struct Mailbox *m, struct Email *e,
     fprintf(fp_tmp, "Resent-Date: %s\n", buf_string(date));
     buf_pool_release(&date);
 
-    char *msgid_str = gen_msgid();
+    char *msgid_str = gen_msgid(sub);
     fprintf(fp_tmp, "Resent-Message-ID: %s\n", msgid_str);
     FREE(&msgid_str);
     mutt_addrlist_write_file(to, fp_tmp, "Resent-To");