diff --git a/src/doveadm/dsync/dsync-brain-mailbox.c b/src/doveadm/dsync/dsync-brain-mailbox.c
index 5dadf97..f71c7aa 100644
--- a/src/doveadm/dsync/dsync-brain-mailbox.c
+++ b/src/doveadm/dsync/dsync-brain-mailbox.c
@@ -322,6 +322,12 @@ int dsync_brain_sync_mailbox_open(struct dsync_brain *brain,
 		exporter_flags |= DSYNC_MAILBOX_EXPORTER_FLAG_TIMESTAMPS;
 	if (brain->hdr_hash_v2)
 		exporter_flags |= DSYNC_MAILBOX_EXPORTER_FLAG_HDR_HASH_V2;
+	if (remote_dsync_box->messages_count == 0) {
+		/* remote mailbox is empty - we don't really need to export
+		   header hashes since they're not going to match anything
+		   anyway. */
+		exporter_flags |= DSYNC_MAILBOX_EXPORTER_FLAG_NO_HDR_HASHES;
+	}
 
 	brain->box_exporter = brain->backup_recv ? NULL :
 		dsync_mailbox_export_init(brain->box, brain->log_scan,
diff --git a/src/doveadm/dsync/dsync-mailbox-export.c b/src/doveadm/dsync/dsync-mailbox-export.c
index c013eb0..361cc55 100644
--- a/src/doveadm/dsync/dsync-mailbox-export.c
+++ b/src/doveadm/dsync/dsync-mailbox-export.c
@@ -63,6 +63,7 @@ struct dsync_mailbox_exporter {
 	unsigned int minimal_dmail_fill:1;
 	unsigned int return_all_mails:1;
 	unsigned int export_received_timestamps:1;
+	unsigned int no_hdr_hashes:1;
 };
 
 static int dsync_mail_error(struct dsync_mailbox_exporter *exporter,
@@ -163,6 +164,10 @@ exporter_get_guids(struct dsync_mailbox_exporter *exporter,
 
 	if (!exporter->mails_have_guids) {
 		/* get header hash also */
+		if (exporter->no_hdr_hashes) {
+			*hdr_hash_r = "";
+			return 1;
+		}
 		if (dsync_mail_get_hdr_hash(mail, exporter->hdr_hash_version, hdr_hash_r) < 0)
 			return dsync_mail_error(exporter, mail, "hdr-stream");
 		return 1;
@@ -505,6 +510,8 @@ dsync_mailbox_export_init(struct mailbox *box,
 		(flags & DSYNC_MAILBOX_EXPORTER_FLAG_TIMESTAMPS) != 0;
 	exporter->hdr_hash_version =
 		(flags & DSYNC_MAILBOX_EXPORTER_FLAG_HDR_HASH_V2) ? 2 : 1;
+	exporter->no_hdr_hashes =
+		(flags & DSYNC_MAILBOX_EXPORTER_FLAG_NO_HDR_HASHES) != 0;
 	p_array_init(&exporter->requested_uids, pool, 16);
 	p_array_init(&exporter->search_uids, pool, 16);
 	hash_table_create(&exporter->export_guids, pool, 0, str_hash, strcmp);
diff --git a/src/doveadm/dsync/dsync-mailbox-export.h b/src/doveadm/dsync/dsync-mailbox-export.h
index c8f9548..02c6aa9 100644
--- a/src/doveadm/dsync/dsync-mailbox-export.h
+++ b/src/doveadm/dsync/dsync-mailbox-export.h
@@ -6,7 +6,8 @@ enum dsync_mailbox_exporter_flags {
 	DSYNC_MAILBOX_EXPORTER_FLAG_MAILS_HAVE_GUIDS	= 0x02,
 	DSYNC_MAILBOX_EXPORTER_FLAG_MINIMAL_DMAIL_FILL	= 0x04,
 	DSYNC_MAILBOX_EXPORTER_FLAG_TIMESTAMPS		= 0x08,
-	DSYNC_MAILBOX_EXPORTER_FLAG_HDR_HASH_V2		= 0x10
+	DSYNC_MAILBOX_EXPORTER_FLAG_HDR_HASH_V2		= 0x10,
+	DSYNC_MAILBOX_EXPORTER_FLAG_NO_HDR_HASHES	= 0x20
 };
 
 struct dsync_mailbox_exporter *