lib/PublicInbox/LeiInput.pm           | 11 ++++++++++-
 lib/PublicInbox/LeiRefreshMailSync.pm |  5 +++++
 t/lei-refresh-mail-sync.t             | 10 ++++++++++

diff --git a/lib/PublicInbox/LeiInput.pm b/lib/PublicInbox/LeiInput.pm
index 8ce445c80d07b3748c8828e63f1d55db8aefb28d..372e0fe19f3ae6d2ba1f7b2461383b1d10ad0f4c 100644
--- a/lib/PublicInbox/LeiInput.pm
+++ b/lib/PublicInbox/LeiInput.pm
@@ -124,7 +124,11 @@ 	} elsif ($input =~ m!\Ahttps?://!i) {
 		handle_http_input($self, $input, @args);
 		return;
 	}
+
+	# local-only below
+	my $ifmt_pfx = '';
 	if ($input =~ s!\A([a-z0-9]+):!!i) {
+		$ifmt_pfx = "$1:";
 		$ifmt = lc($1);
 	} elsif ($input =~ /\.(?:patch|eml)\z/i) {
 		$ifmt = 'eml';
@@ -172,10 +176,15 @@ 			$mdr->maildir_each_eml($input,
 						$self->can('input_maildir_cb'),
 						$self, @args);
 		}
+	} elsif ($self->{missing_ok} && !-e $input) { # don't ->fail
+		$self->folder_missing("$ifmt:$input");
 	} else {
-		$lei->fail("$input unsupported (TODO)");
+		$lei->fail("$ifmt_pfx$input unsupported (TODO)");
 	}
 }
+
+# subclasses should overrride this (see LeiRefreshMailSync)
+sub folder_missing { die "BUG: ->folder_missing undefined for $_[0]" }
 
 sub bad_http ($$;$) {
 	my ($lei, $url, $alt) = @_;
diff --git a/lib/PublicInbox/LeiRefreshMailSync.pm b/lib/PublicInbox/LeiRefreshMailSync.pm
index 4cae1536047616e0e625dad550c201daee8c5bdf..19f64b58f7c811574b8270c5f3584b7fe499fe36 100644
--- a/lib/PublicInbox/LeiRefreshMailSync.pm
+++ b/lib/PublicInbox/LeiRefreshMailSync.pm
@@ -11,6 +11,11 @@ use PublicInbox::LeiExportKw;
 use PublicInbox::InboxWritable qw(eml_from_path);
 use PublicInbox::Import;
 
+sub folder_missing {
+	my ($self, $folder) = @_;
+	$self->{lei}->{sto}->ipc_do('lms_forget_folders', $folder);
+}
+
 sub prune_mdir { # lms->each_src callback
 	my ($oidbin, $id, $self, $mdir) = @_;
 	my @try = $$id =~ /:2,[a-zA-Z]*\z/ ? qw(cur new) : qw(new cur);
diff --git a/t/lei-refresh-mail-sync.t b/t/lei-refresh-mail-sync.t
index ff558277f8cc003d751c0f47a8aae4ce9e67f9c7..d343801185f3bc1d0dbf17b78ee2f361fc382121 100644
--- a/t/lei-refresh-mail-sync.t
+++ b/t/lei-refresh-mail-sync.t
@@ -3,6 +3,7 @@ # Copyright (C) all contributors <meta@public-inbox.org>
 # License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
 use strict; use v5.10.1; use PublicInbox::TestCommon;
 require_mods(qw(lei));
+use File::Path qw(remove_tree);
 
 my $stop_daemon = sub { # needed since we don't have inotify
 	lei_ok qw(daemon-pid);
@@ -62,6 +63,15 @@ 	lei_ok 'refresh-mail-sync', "Maildir:$d";
 	lei_ok 'inspect', "blob:$oid";
 	is_deeply(json_utf8->decode($lei_out), $exp1,
 		'replaced file noted again');
+
+	$stop_daemon->();
+
+	remove_tree($d);
+	lei_ok 'refresh-mail-sync', '--all';
+	lei_ok 'inspect', "blob:$oid";
+	is($lei_out, '{}', 'no known locations after "removal"');
+	lei_ok 'ls-mail-sync';
+	is($lei_out, '', 'no sync left when folder is gone');
 });
 
 done_testing;