lib/PublicInbox/IMAP.pm | 3 +++

diff --git a/lib/PublicInbox/IMAP.pm b/lib/PublicInbox/IMAP.pm
index 77e8af12fa9e9e4ac8b47a7b9226b1084df94332..13f415cf8d64766a30075befebb36f5e5a7f5f64 100644
--- a/lib/PublicInbox/IMAP.pm
+++ b/lib/PublicInbox/IMAP.pm
@@ -80,6 +80,9 @@ my @MoY = qw(Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec);
 my %MoY;
 @MoY{@MoY} = (0..11);
 
+# RFC 3501 5.4. Autologout Timer needs to be >= 30min
+$PublicInbox::DS::EXPTIME = 60 * 30;
+
 sub greet ($) {
 	my ($self) = @_;
 	my $capa = capa($self);