update mail notifier
update mail notifier

* change default `mail_folder` location for :file `delivery_method`
* expand path for `sendmail` location

rics3n/backup,hiphapis/backup,ccoenen/backup,martincik/backup,bernd/backup,skcript/backup,pollosp/backup,interu/backup,pollosp/backup,otzy007/backup,otzy007/backup,interu/backup,McStork/backup,hiphapis/backup,zBMNForks/backup,sferik/backup,rics3n/backup,backup/backup,scalp42/backup,otzy007/backup,rics3n/backup,martincik/backup,scalp42/backup,reedloden/backup,ccoenen/backup,backup/backup,ccoenen/backup,scalp42/backup,reedloden/backup,McStork/backup,pat/backup,martincik/backup,tian-xiaobo/backup,tian-xiaobo/backup,pawelduda/backup,skcript/backup,juliancheal/backup,interu/backup,bernd/backup,zires/backup,zBMNForks/backup,pawelduda/backup,skcript/backup,zires/backup,pollosp/backup,zBMNForks/backup,reedloden/backup,tian-xiaobo/backup,bukalapak/backup,McStork/backup,john/backup,pawelduda/backup,backup/backup,zires/backup,hiphapis/backup