mail/dma: Implement cronjob to flush emails

Add a new cronjob to flush emails every 30 minutes and change
pkg-message to let users know about it.

PR:		261532
Sponsored by:	Rubicon Communications, LLC ("Netgate")

mail/dma/Makefile

@@ -28,7 +28,7 @@ CFLAGS+=	-DCONF_PATH='\"${PREFIX}/etc/dma\"' -DDMA_GROUP='\"mail\"' \
 LDFLAGS+=	-L${OPENSSLLIB}
 
 PORTSCOUT=	limit:^[0-9\.]*$$
-SUB_FILES=	pkg-message
+SUB_FILES=	dma_cron pkg-message
 
 BUILD_WRKSRC=	${WRKSRC}/bsd
 INSTALL_WRKSRC=	${WRKSRC}/bsd
@@ -43,11 +43,13 @@ post-patch:
 		${WRKSRC}/bsd/dma-mbox-create/Makefile
 
 post-install:
-	${MKDIR} ${STAGEDIR}${ETCDIR}
+	${MKDIR} ${STAGEDIR}${ETCDIR}/cron.d
 	${MKDIR} ${STAGEDIR}/var/spool/dma
 	${INSTALL_DATA} ${WRKSRC}/dma.conf \
 		${STAGEDIR}${ETCDIR}/dma.conf.sample
 	${INSTALL_DATA} ${WRKSRC}/auth.conf \
 		${STAGEDIR}${ETCDIR}/auth.conf.sample
+	${INSTALL_DATA} ${WRKDIR}/dma_cron \
+		${STAGEDIR}${ETCDIR}/cron.d/dma
 
 .include <bsd.port.mk>

mail/dma/files/dma_cron.in

@@ -0,0 +1,5 @@
+SHELL=/bin/sh
+PATH=/etc:/bin:/sbin:/usr/bin:/usr/sbin
+
+# See crontab(5) for field format.
+*/30 * * * * root %%PREFIX%%/libexec/dma -q

mail/dma/files/pkg-message.in

@@ -33,10 +33,8 @@ shutdown, add the following to rc.conf as well:
 
 dma_flushq_enable="YES"
 
-you can also add a cronjob to do regular mailq flushes using the following
-command:
-
-%%PREFIX%%/libexec/dma -q
+A crontab configuration to flush every 30 minutes was added to
+%%PREFIX%%/etc/cron.d/dma.
 
 And you can disable some sendmail specific daily maintenance routines in your
 /etc/periodic.conf file:

mail/dma/pkg-plist

@@ -1,3 +1,4 @@
+%%ETCDIR%%/cron.d/dma
 @(root,mail,2555) libexec/dma
 @(root,mail,4554) libexec/dma-mbox-create
 @sample(root,mail,0644) etc/dma/dma.conf.sample