For personal reasons I needed a way to set the sender address for mails send by cron. I read that some cron versions support a MAILFROM variable for this purpose (https://serverfault.com/questions/121121/how-to-change-from-field-for-emails-from-cron#437319). I therefore wrote a patch for the current xenial cron package to support this variable. diff --from-file cron-3.0pl1.orig cron-3.0pl1.orig/crontab.5 cron-patch/crontab.5 103c103,104 < owner of the crontab. --- > owner of the crontab. If MAILFROM is defined (and non-empty), it will be used > as the envelope sender address, otherwise, ''root'' will be used. diff --from-file cron-3.0pl1.orig cron-3.0pl1.orig/do_command.c cron-patch/do_command.c 81a82,100 > /* Check for arguments */ > static char* check_env_argument(char *argument) > { > if (argument) { > const char *end; > > /* These chars have to match those cron_popen() > * uses to split the command string */ > argument += strspn(argument, " \t\n"); > end = argument + strcspn(argument, " \t\n"); > if (*argument == '-' || *end != '\0') { > printf("Bad Mailto/Mailfrom karma.\n"); > log_it("CRON",getpid(),"error","bad mailto/mailfrom"); > argument = NULL; > } > } > return argument; > } > 132c151 < char *usernm, *mailto; --- > char *usernm, *mailto, *mailfrom; 155a175 > mailfrom = env_get("MAILFROM", e->envp); 158,171c178,180 < if (mailto) { < const char *end; < < /* These chars have to match those cron_popen() < * uses to split the command string */ < mailto += strspn(mailto, " \t\n"); < end = mailto + strcspn(mailto, " \t\n"); < if (*mailto == '-' || *end != '\0') { < printf("Bad Mailto karma.\n"); < log_it("CRON",getpid(),"error","bad mailto"); < mailto = NULL; < } < } < --- > mailto = check_env_argument(mailto); > mailfrom = check_env_argument(mailfrom); > 532a542,545 > // get name of sender > if (mailfrom && !*mailfrom) > mailfrom = NULL; > 561c574,578 < fprintf(mail, "From: root (Cron Daemon)\n"); --- > if (mailfrom) { > fprintf(mail, "From: %s\n", mailfrom); > } else { > fprintf(mail, "From: root (Cron Daemon)\n"); > } It has been tested on Ubuntu 16.04 in conjunction with the ssmtp package to send the mail. Not setting MAILFROM, setting it to "" and setting a valid mail worked for my purposes. I'll just leave this here

Ubuntucron package

History of question #630386

Ubuntu
cron package