diff -up dovecot-2.2.36/dovecot.service.in.waitonline dovecot-2.2.36/dovecot.service.in
--- dovecot-2.2.36/dovecot.service.in.waitonline	2018-04-30 15:52:05.000000000 +0200
+++ dovecot-2.2.36/dovecot.service.in	2018-06-12 15:34:22.459995078 +0200
@@ -8,10 +8,11 @@
 Description=Dovecot IMAP/POP3 email server
 Documentation=man:dovecot(1)
 Documentation=http://wiki2.dovecot.org/
-After=local-fs.target network.target
+After=local-fs.target network.target network-online.target

 [Service]
 Type=forking
+ExecStartPre=/usr/libexec/dovecot/prestartscript
 ExecStart=@sbindir@/dovecot
 PIDFile=@rundir@/master.pid
 ExecReload=@bindir@/doveadm reload
