diff -up dovecot-2.3.15/dovecot.service.in.waitonline dovecot-2.3.15/dovecot.service.in
--- dovecot-2.3.15/dovecot.service.in.waitonline	2021-06-21 20:19:19.560494654 +0200
+++ dovecot-2.3.15/dovecot.service.in	2021-06-21 20:21:17.443066248 +0200
@@ -15,6 +15,7 @@ After=local-fs.target network-online.tar
 
 [Service]
 Type=@systemdservicetype@
+ExecStartPre=/usr/libexec/dovecot/prestartscript
 ExecStart=@sbindir@/dovecot -F
 ExecReload=@bindir@/doveadm reload
 ExecStop=@bindir@/doveadm stop