diff --git a/data/conf/dovecot/dovecot.conf b/data/conf/dovecot/dovecot.conf
index b6f7318c9..e6744ee40 100644
--- a/data/conf/dovecot/dovecot.conf
+++ b/data/conf/dovecot/dovecot.conf
@@ -53,7 +53,7 @@ mail_shared_explicit_inbox = yes
 mail_prefetch_count = 30
 passdb {
   driver = lua
-  args = file=/etc/dovecot/auth/passwd-verify.lua blocking=yes
+  args = file=/etc/dovecot/auth/passwd-verify.lua blocking=yes cache_key=%u:%w
   result_success = return-ok
   result_failure = continue
   result_internalfail = continue
@@ -125,6 +125,7 @@ service managesieve-login {
 }
 service imap-login {
   service_count = 1
+  process_min_avail = 2
   process_limit = 10000
   vsz_limit = 1G
   user = dovenull
@@ -140,6 +141,7 @@ service imap-login {
 }
 service pop3-login {
   service_count = 1
+  process_min_avail = 1
   vsz_limit = 1G
   inet_listener pop3_haproxy {
     port = 10110
@@ -274,10 +276,10 @@ service stats {
   }
 }
 imap_max_line_length = 2 M
-#auth_cache_verify_password_with_worker = yes
-#auth_cache_negative_ttl = 0
-#auth_cache_ttl = 30 s
-#auth_cache_size = 2 M
+auth_cache_verify_password_with_worker = yes
+auth_cache_negative_ttl = 60s
+auth_cache_ttl = 300s
+auth_cache_size = 10M
 service replicator {
   process_min_avail = 1
 }