I'm not sure, I already followed the other steps in the guide, and I'd like to get the sieve working, since I have been getting like 200 spam emails a day.
Here is the output of systemctl status dovecot.service:
● dovecot.service - Dovecot IMAP/POP3 email server
Loaded: loaded (/usr/lib/systemd/system/dovecot.service; enabled; vendor preset: disabled)
Active: failed (Result: exit-code) since Sat 2018-11-17 04:33:48 UTC; 1 day 18h ago
Process: 13942 ExecStart=/usr/sbin/dovecot -F (code=exited, status=89)
Process: 13936 ExecStartPre=/usr/libexec/dovecot/prestartscript (code=exited, status=0/SUCCESS)
Main PID: 13942 (code=exited, status=89)
Nov 17 04:33:48 cyprinidae.utahfishkeepers.us systemd[1]: Starting Dovecot IM...
Nov 17 04:33:48 cyprinidae.utahfishkeepers.us systemd[1]: Started Dovecot IMA...
Nov 17 04:33:48 cyprinidae.utahfishkeepers.us dovecot[13942]: Fatal: service(...
Nov 17 04:33:48 cyprinidae.utahfishkeepers.us systemd[1]: dovecot.service: ma...
Nov 17 04:33:48 cyprinidae.utahfishkeepers.us systemd[1]: Unit dovecot.servic...
Nov 17 04:33:48 cyprinidae.utahfishkeepers.us systemd[1]: dovecot.service fai...
Hint: Some lines were ellipsized, use -l to show in full.
and journalctl -xe:
Nov 18 22:50:08 cyprinidae.utahfishkeepers.us postfix/smtpd[29474]: fatal: no SASL a
Nov 18 22:50:08 cyprinidae.utahfishkeepers.us postfix/smtpd[29473]: connect from unk
Nov 18 22:50:08 cyprinidae.utahfishkeepers.us postfix/smtpd[29473]: warning: SASL: C
Nov 18 22:50:08 cyprinidae.utahfishkeepers.us postfix/smtpd[29473]: fatal: no SASL a
Nov 18 22:50:09 cyprinidae.utahfishkeepers.us postfix/master[13397]: warning: proces
Nov 18 22:50:09 cyprinidae.utahfishkeepers.us postfix/master[13397]: warning: /usr/l
Nov 18 22:50:09 cyprinidae.utahfishkeepers.us postfix/smtpd[29471]: connect from unk
Nov 18 22:50:09 cyprinidae.utahfishkeepers.us postfix/smtpd[29471]: warning: SASL: C
Nov 18 22:50:09 cyprinidae.utahfishkeepers.us postfix/smtpd[29471]: fatal: no SASL a
Nov 18 22:50:09 cyprinidae.utahfishkeepers.us postfix/master[13397]: warning: proces
Nov 18 22:50:09 cyprinidae.utahfishkeepers.us postfix/master[13397]: warning: proces
Nov 18 22:50:10 cyprinidae.utahfishkeepers.us postfix/master[13397]: warning: proces
Nov 18 22:50:10 cyprinidae.utahfishkeepers.us postfix/smtpd[29472]: connect from unk
Nov 18 22:50:10 cyprinidae.utahfishkeepers.us postfix/smtpd[29472]: warning: SASL: C
Nov 18 22:50:10 cyprinidae.utahfishkeepers.us postfix/smtpd[29472]: fatal: no SASL a
Nov 18 22:50:11 cyprinidae.utahfishkeepers.us dhclient[29495]: DHCPDISCOVER on lan4
Nov 18 22:50:11 cyprinidae.utahfishkeepers.us postfix/master[13397]: warning: proces
Nov 18 22:50:12 cyprinidae.utahfishkeepers.us postfix/smtpd[29492]: connect from unk
Nov 18 22:50:12 cyprinidae.utahfishkeepers.us postfix/smtpd[29492]: warning: SASL: C
Nov 18 22:50:12 cyprinidae.utahfishkeepers.us postfix/smtpd[29492]: fatal: no SASL a
Nov 18 22:50:13 cyprinidae.utahfishkeepers.us postfix/master[13397]: warning: proces
Nov 18 22:50:23 cyprinidae.utahfishkeepers.us dhclient[29495]: DHCPDISCOVER on lan4
Nov 18 22:50:38 cyprinidae.utahfishkeepers.us dhclient[29495]: DHCPDISCOVER on lan4