MANIFEST                |  1 +
 xt/cmp-imapd-compress.t | 83 +++++++++++++++++++++++++++++++++++++++++++++++++++++

diff --git a/MANIFEST b/MANIFEST
index 82f047f36232dd67e548f65a1c0cd84a07ad3c7c..f74852b6e908168ebf8095771b8d90fb642fa773 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -346,6 +346,7 @@ t/www_listing.t
 t/www_static.t
 t/x-unknown-alpine.eml
 t/xcpdb-reshard.t
+xt/cmp-imapd-compress.t
 xt/cmp-msgstr.t
 xt/cmp-msgview.t
 xt/eml_check_limits.t
diff --git a/xt/cmp-imapd-compress.t b/xt/cmp-imapd-compress.t
new file mode 100644
index 0000000000000000000000000000000000000000..b12cf74e2d565e2f2e83008f139308f4dd7d224b
--- /dev/null
+++ b/xt/cmp-imapd-compress.t
@@ -0,0 +1,83 @@
+#!perl -w
+# Copyright (C) 2020 all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+use strict;
+use Test::More;
+use PublicInbox::TestCommon;
+require_mods('Data::Dumper');
+Data::Dumper->import('Dumper');
+my $inboxdir = $ENV{GIANT_INBOX_DIR};
+(defined($inboxdir) && -d $inboxdir) or
+	plan skip_all => "GIANT_INBOX_DIR not defined for $0";
+plan skip_all => "bad characters in $inboxdir" if $inboxdir =~ m![^\w\.\-/]!;
+my ($tmpdir, $for_destroy) = tmpdir();
+my $cfg = "$tmpdir/cfg";
+my $mailbox = 'inbox.test';
+{
+	open my $fh, '>', $cfg or BAIL_OUT "open: $!";
+	print $fh <<EOF or BAIL_OUT "print: $!";
+[publicinbox "test"]
+	newsgroup = $mailbox
+	address = test\@example.com
+	inboxdir = $inboxdir
+EOF
+	close $fh or BAIL_OUT "close: $!";
+}
+my ($out, $err) = ("$tmpdir/stdout.log", "$tmpdir/stderr.log");
+my $sock = tcp_server();
+my $cmd = [ '-imapd', '-W0', "--stdout=$out", "--stderr=$err"];
+my $env = { PI_CONFIG => $cfg };
+my $td = start_script($cmd, $env, { 3 => $sock }) or BAIL_OUT "-imapd: $?";
+my ($host, $port) = ($sock->sockhost, $sock->sockport);
+my $c = tcp_connect($sock);
+like(readline($c), qr/CAPABILITY /, 'got greeting');
+undef $c;
+
+SKIP: {
+	require_mods('Mail::IMAPClient', 3);
+	unless ($ENV{RT_132720_FIXED}) {
+		my $bug = 'https://rt.cpan.org/Ticket/Display.html?id=132720';
+		skip "<$bug>, RT_132720_FIXED not defined", 3;
+	}
+	my %opt = (Server => $host, Port => $port,
+			User => 'u', Password => 'p', Clear => 1);
+	my $uc = Mail::IMAPClient->new(%opt);
+	my $c = Mail::IMAPClient->new(%opt);
+	ok($c->compress, 'enabled compression');
+	ok $c->examine($mailbox), 'compressed EXAMINE-ed';
+	ok $uc->examine($mailbox), 'uncompress EXAMINE-ed';
+	my $range = $uc->search('all');
+	for my $uid (@$range) {
+		my $A = $uc->fetch_hash($uid, 'BODY[]');
+		my $B = $c->fetch_hash($uid, 'BODY[]');
+		if (!is_deeply($A, $B, "$uid identical")) {
+			diag Dumper([$A, $B]);
+			diag Dumper([$uc, $c]);
+			last;
+		}
+	}
+	$uc->logout;
+	$c->logout;
+}
+
+SKIP: {
+	require_mods('Mail::IMAPTalk', 3);
+	my %opt = (Server => $host, Port => $port, UseSSL => 0,
+		Username => 'u', Password => 'p', Uid => 1);
+	my $uc = Mail::IMAPTalk->new(%opt) or BAIL_OUT 'IMAPTalk->new';
+	my $c = Mail::IMAPTalk->new(%opt, UseCompress => 1) or
+		BAIL_OUT 'IMAPTalk->new(UseCompress => 1)';
+	ok $c->examine($mailbox), 'compressed EXAMINE-ed';
+	ok $uc->examine($mailbox), 'uncompress EXAMINE-ed';
+	my $range = $uc->search('all');
+	for my $uid (@$range) {
+		my $A = $uc->fetch($uid, 'rfc822');
+		my $B = $c->fetch($uid, 'rfc822');
+		if (!is_deeply($A, $B, "$uid identical")) {
+			diag Dumper([$A, $B]);
+			diag Dumper([$uc, $c]);
+			last;
+		}
+	}
+}
+done_testing;