diff --git a/imapserver/server.go b/imapserver/server.go
index f1ff40f..16264e9 100644
--- a/imapserver/server.go
+++ b/imapserver/server.go
@@ -2967,7 +2967,11 @@ func (c *conn) cmdxCopy(isUID bool, tag, cmd string, p *parser) {
 				m.ID = 0
 				m.UID = uidFirst + store.UID(i)
 				m.MailboxID = mbDst.ID
-				m.MailboxOrigID = mbSrc.ID
+				if mbSrc.Name == conf.RejectsMailbox && m.MailboxDestinedID != 0 {
+					// Incorrectly delivered to Rejects mailbox. Adjust MailboxOrigID so this message
+					// is used for reputation calculation during future deliveries.
+					m.MailboxOrigID = m.MailboxDestinedID
+				}
 				m.TrainedJunk = nil
 				m.JunkFlagsForMailbox(mbDst.Name, conf)
 				err := tx.Insert(&m)
@@ -3092,7 +3096,7 @@ func (c *conn) cmdxMove(isUID bool, tag, cmd string, p *parser) {
 
 	c.account.WithWLock(func() {
 		c.xdbwrite(func(tx *bstore.Tx) {
-			c.xmailboxID(tx, c.mailboxID) // Validate.
+			mbSrc := c.xmailboxID(tx, c.mailboxID) // Validate.
 			mbDst = c.xmailbox(tx, name, "TRYCREATE")
 			if mbDst.ID == c.mailboxID {
 				xuserErrorf("cannot move to currently selected mailbox")
@@ -3128,6 +3132,11 @@ func (c *conn) cmdxMove(isUID bool, tag, cmd string, p *parser) {
 					xserverErrorf("internal error: got uid %d, expected %d, for index %d", m.UID, uids[i], i)
 				}
 				m.MailboxID = mbDst.ID
+				if mbSrc.Name == conf.RejectsMailbox && m.MailboxDestinedID != 0 {
+					// Incorrectly delivered to Rejects mailbox. Adjust MailboxOrigID so this message
+					// is used for reputation calculation during future deliveries.
+					m.MailboxOrigID = m.MailboxDestinedID
+				}
 				m.UID = uidnext
 				m.JunkFlagsForMailbox(mbDst.Name, conf)
 				uidnext++
diff --git a/smtpserver/analyze.go b/smtpserver/analyze.go
index 61da216..db68ede 100644
--- a/smtpserver/analyze.go
+++ b/smtpserver/analyze.go
@@ -163,8 +163,8 @@ func analyze(ctx context.Context, log *mlog.Log, resolver dns.Resolver, d delive
 		err = d.acc.DB.Read(func(tx *bstore.Tx) error {
 			// Set message MailboxID to which mail will be delivered. Reputation is
 			// per-mailbox. If referenced mailbox is not found (e.g. does not yet exist), we
-			// can still use determine a reputation because we also base it on outgoing
-			// messages and those account-global.
+			// can still determine a reputation because we also base it on outgoing
+			// messages and those are account-global.
 			mailbox := d.rcptAcc.destination.Mailbox
 			if mailbox == "" {
 				mailbox = "Inbox"
@@ -174,7 +174,15 @@ func analyze(ctx context.Context, log *mlog.Log, resolver dns.Resolver, d delive
 			}
 			mb := d.acc.MailboxFindX(tx, mailbox)
 			if mb != nil {
+				// We want to deliver to mb.ID, but this message may be rejected and sent to the
+				// Rejects mailbox instead, which MailboxID overwritten. Record the ID in
+				// MailboxDestinedID too. If the message is later moved out of the Rejects mailbox,
+				// we'll adjust the MailboxOrigID so it gets taken into account during reputation
+				// calculating in future deliveries. If we end up delivering to the intended
+				// mailbox (i.e. not rejecting), MailboxDestinedID is cleared during delivery so we
+				// don't store it unnecessarily.
 				d.m.MailboxID = mb.ID
+				d.m.MailboxDestinedID = mb.ID
 			} else {
 				log.Debug("mailbox not found in database", mlog.Field("mailbox", mailbox))
 			}
diff --git a/store/account.go b/store/account.go
index 77eb036..5959109 100644
--- a/store/account.go
+++ b/store/account.go
@@ -229,11 +229,23 @@ type Message struct {
 	UID       UID   `bstore:"nonzero"` // UID, for IMAP. Set during deliver.
 	MailboxID int64 `bstore:"nonzero,unique MailboxID+UID,index MailboxID+Received,ref Mailbox"`
 
-	// Mailbox message originally delivered to. I.e. not changed when moved to Trash or
-	// Junk. Useful for per-mailbox reputation. Not a bstore reference to prevent
-	// having to update all messages in a mailbox when the original mailbox is removed.
-	// Use of this field requires checking if the mailbox still exists.
-	MailboxOrigID int64
+	// MailboxOrigID is the mailbox the message was originally delivered to. Typically
+	// Inbox or Rejects, but can also be Postmaster and TLS/DMARC reporting addresses.
+	// MailboxOrigID is not changed when the message is moved to another mailbox, e.g.
+	// Archive/Trash/Junk. Used for per-mailbox reputation.
+	//
+	// MailboxDestinedID is normally 0, but when a message is delivered to the Rejects
+	// mailbox, it is set to the intended mailbox according to delivery rules,
+	// typically that of Inbox. When such a message is moved out of Rejects, the
+	// MailboxOrigID is corrected by setting it to MailboxDestinedID. This ensures the
+	// message is used for reputation calculation for future deliveries to that
+	// mailbox.
+	//
+	// These are not bstore references to prevent having to update all messages in a
+	// mailbox when the original mailbox is removed. Use of these fields requires
+	// checking if the mailbox still exists.
+	MailboxOrigID     int64
+	MailboxDestinedID int64
 
 	Received time.Time `bstore:"default now,index"`
 
@@ -600,6 +612,11 @@ func (a *Account) DeliverX(log *mlog.Log, tx *bstore.Tx, m *Message, msgFile *os
 		m.ParsedBuf = buf
 	}
 
+	// If we are delivering to the originally intended mailbox, no need to store the mailbox ID again.
+	if m.MailboxDestinedID != 0 && m.MailboxDestinedID == m.MailboxOrigID {
+		m.MailboxDestinedID = 0
+	}
+
 	err = tx.Insert(m)
 	xcheckf(err, "inserting message")