初めまして。
以下の設定で、SMTPプロセスの監視を行っています。
Zabbix Server:
OS:CentOS Linux release 7.5.1804 (Core)
# /usr/sbin/zabbix_server -V
zabbix_server (Zabbix) 3.0.14
Revision 76338 27 December 2017, compilation time: Dec 27 2017 16:18:17
Copyright (C) 2017 Zabbix SIA
License GPLv2+: GNU GPL version 2 or later .
This is free software: you are free to change and redistribute it according to
the license. There is NO WARRANTY, to the extent permitted by law.
Trigger:
親トリガー：Template App SMTP Service
名前 ：SMTP service is down on {HOST.NAME}