Postfix para continuamente

Question

Eu acabei de configurar o Sendgrid com sucesso em uma Instância do Google Cloud, que é o CPanel instalado no CentOS. Aqui Eu fiz isso.

Quando instalar o Postfix, tenho que remover o exim4 instalado atualmente. A instalação é bem sucedida, mas eu encontrei, por vezes, o Postfix está parado. Se eu começar a usar # postfix start novamente, ele será interrompido em alguns minutos.

Abaixo está o maillog:

# tail -n 30 /var/log/maillog

Jul 28 04:24:33 myhost postfix/qmgr[15174]: BAD9D110BEAB3: from=<[email protected]>, size=3665, nrcpt=1 (queue active)
Jul 28 04:24:33 myhost postfix/smtp[15181]: BAD9D110BEAB3: to=<[email protected]>, relay=smtp.sendgrid.net[167.89.125.25]:2525, delay=152, delays=152/0.02/0.1/0.03, dsn=2.0.0, status=sent (250 Ok: queued as q4j-M5JVRM61Sw9du237_g)
Jul 28 04:24:33 myhost postfix/qmgr[15174]: BAD9D110BEAB3: removed
Jul 28 04:24:33 myhost postfix/smtp[15177]: AA9A8110BEAA3: to=<[email protected]>, relay=smtp.sendgrid.net[167.89.125.25]:2525, delay=577, delays=576/0.02/0.11/0.06, dsn=2.0.0, status=sent (250 Ok: queued as AcEHW3P5Q5K7PgnA0qvsYQ)
Jul 28 04:24:33 myhost postfix/qmgr[15174]: AA9A8110BEAA3: removed
Jul 28 04:24:33 myhost postfix/smtp[15180]: B5A5B110BEAB2: to=<[email protected]>, relay=smtp.sendgrid.net[167.89.125.25]:2525, delay=152, delays=152/0.01/0.09/0.06, dsn=2.0.0, status=sent (250 Ok: queued as QumlXDnNQHekR3TnPfC_Kg)
Jul 28 04:24:33 myhost postfix/qmgr[15174]: B5A5B110BEAB2: removed
Jul 28 04:24:33 myhost postfix/smtp[15179]: B29A2110BEAA4: to=<[email protected]>, relay=smtp.sendgrid.net[167.89.125.25]:2525, delay=577, delays=576/0.02/0.18/0.02, dsn=2.0.0, status=sent (250 Ok: queued as k-HSDlzjTPiR3mxxXWZj2A)
Jul 28 04:24:33 myhost postfix/qmgr[15174]: B29A2110BEAA4: removed
Jul 28 04:29:35 myhost spamc[15925]: connect to spamd on ::1 failed, retrying (#1 of 3): Connection refused
Jul 28 04:29:36 myhost spamd[1195]: zoom: able to use 996/997 'body_0' compiled rules (99.899%)
Jul 28 04:29:37 myhost spamd[1195]: spamd: server started on IO::Socket::INET [_]:783 (running version 3.4.1)
Jul 28 04:29:37 myhost spamd[1195]: spamd: server pid: 1195
Jul 28 04:29:37 myhost spamd[1195]: spamd: server successfully spawned child process, pid 15934
Jul 28 04:29:37 myhost spamd[1195]: prefork: child states: B
Jul 28 04:29:37 myhost spamd[15934]: spamd: connection from localhost [127.0.0.1]:39080 to port 783, fd 5
Jul 28 04:29:37 myhost spamd[1195]: spamd: server successfully spawned child process, pid 15935
Jul 28 04:29:37 myhost spamd[1195]: prefork: adjust: 0 idle children less than 1 minimum idle children. Increasing spamd children: 15935 started.
Jul 28 04:29:37 myhost spamd[1195]: prefork: child states: BI
Jul 28 04:29:37 myhost spamd[1195]: prefork: child states: II
Jul 28 04:29:37 myhost spamd[1195]: prefork: adjust: 2 idle children more than 1 maximum idle children. Decreasing spamd children: 15935 killed.
Jul 28 04:29:37 myhost spamd[1195]: prefork: child states: IK
Jul 28 04:29:37 myhost spamd[1195]: spamd: handled cleanup of child pid [15935] due to SIGCHLD: interrupted, signal 2 (0002)
Jul 28 04:29:37 myhost dovecot: pop3-login: Aborted login (no auth attempts in 0 secs): user=<>, rip=127.0.0.1, lip=127.0.0.1, secured, session=<6cb+IFlVIr1/AAAB>
Jul 28 04:29:38 myhost dovecot: lmtp(15985): Connect from local
Jul 28 04:29:38 myhost dovecot: lmtp(15985): Disconnect from local: Successful quit
Jul 28 04:29:38 myhost dovecot: imap-login: Login: user=<__cpanel__service__auth__imap__x4omw2slm18rtsvbmuqztk47y34ogk65i4b9jtgduyu1py...>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=15998, secured, session=<lGoLIVlV9Ld/AAAB>
Jul 28 04:29:38 myhost dovecot: imap(__cpanel__service__auth__imap__x4omw2slm18rtsvbmuqztk47y34ogk65i4b9jtgduyu1pylltnu7jebtjldvddpu): Logged out in=11, out=470, bytes=11/470
Jul 28 04:29:38 myhost postfix/master[15172]: terminating on signal 15
Jul 28 04:29:40 myhost postfix/sendmail[16036]: fatal: Recipient addresses must be specified on the command line or via the -t option

Eu quero saber o que está acontecendo aqui e uma maneira de manter o Postfix funcionando continuamente?