sSMTP is behaving strangely

Question

I have bash script that runs daily on customer's Ubuntu 20.04 server. This simple script rsyncs a bunch of files from one location to the another. While copying, it creates a log file with basic info: start time, end time, number of copied files. After backup ends, it uses ssmtp to send that report to my email. The script looks like this:

#!/bin/bash
DAN=monday
rm -R /backup/$DAN/*
touch /backup/$DAN/backup.log
DATE=date +%d.%m.%Y.
TIME=date +%R
echo        Subject: Backup report for date $DATE >> /backup/$DAN/backup.log
echo        Content-Type: text/html; charset="utf8" >> /backup/$DAN/backup.log
echo
echo  >> /backup/$DAN/backup.log
echo "Backup for date $DATE" >> /backup/$DAN/backup.log
echo >> /backup/$DAN/backup.log
echo "Starting daily at 22.00h" >> /backup/$DAN/backup.log
echo >> /backup/$DAN/bekap.log
echo "Starting time is $TIME" >> /backup/$DAN/backup.log
rsync -avh --progress -h /mnt/share/ /backup/$DAN
SIZE=du -sh /backup/$DAN/
FILES=tree -f /backup/$DAN/ | wc -l
KILLTIME=date +%R
echo >> /backup/$DAN/backup.log
echo "Ending time is $KILLTIME" >> /backup/$DAN/backup.log
echo >> /backup/$DAN/backup.log
echo
echo "Total copied size is $SIZE" >> /backup/$DAN/backup.log
echo >> /backup/$DAN/backup.log
echo
echo "Copied $FILES files" >> /backup/$DAN/backup.log
echo >> /backup/$DAN/backup.log
ssmtp -v -F "Backup report" me@mydomain.com < /backup/$DAN/backup.log

Now, if I run the script manually, logged in with sudo, it works fine and I receive my report as expected. But if I crontab execute the same script, it replaces sender and receiver and mail is not delivered!

Manually executed script create log entry like this:

Oct 18 08:49:47 BKP-ASUS sSMTP[265073]: Set MailHub="smtp.gmail.com"
Oct 18 08:49:47 BKP-ASUS sSMTP[265073]: via SMTP Port Number="465"
Oct 18 08:49:47 BKP-ASUS sSMTP[265073]: Creating SSL connection to host
Oct 18 08:49:47 BKP-ASUS sSMTP[265073]: SSL connection using ECDHE_RSA_AES_256_GCM_SHA384
Oct 18 08:49:47 BKP-ASUS sSMTP[265073]: 220 smtp.gmail.com ESMTP 
cz16-20020a0564021cb000b00535204ffdb4sm2275216edb.72 - gsmtp
Oct 18 08:49:47 BKP-ASUS sSMTP[265073]: EHLO host.domain.com 
Oct 18 08:49:47 BKP-ASUS sSMTP[265073]: 250 SMTPUTF8
Oct 18 08:49:47 BKP-ASUS sSMTP[265073]: AUTH LOGIN
Oct 18 08:49:47 BKP-ASUS sSMTP[265073]: 334 VXNlcm5hbWU6
Oct 18 08:49:47 BKP-ASUS sSMTP[265073]: b2JhdmVzdGVuamFAa29udHJvbHNpc3RlbS5ycw==
Oct 18 08:49:47 BKP-ASUS sSMTP[265073]: 334 UGFzc3dvcmQ6
Oct 18 08:49:47 BKP-ASUS sSMTP[265073]: ZGZ3dW1veHdvbGZ0c3B1eA==
Oct 18 08:49:47 BKP-ASUS sSMTP[265073]: 235 2.7.0 Accepted
Oct 18 08:49:47 BKP-ASUS sSMTP[265073]: MAIL FROM:<recipient@domain.com>
Oct 18 08:49:47 BKP-ASUS sSMTP[265073]: 250 2.1.0 OK 
cz16-20020a0564021cb000b00535204ffdb4sm2275216edb.72 - gsmtp
Oct 18 08:49:47 BKP-ASUS sSMTP[265073]: RCPT TO:<me@mydomain.com>
Oct 18 08:49:47 BKP-ASUS sSMTP[265073]: 250 2.1.5 OK cz16-20020a0564021cb000b00535204ffdb4sm2275216edb.72 - gsmtp
Oct 18 08:49:47 BKP-ASUS sSMTP[265073]: DATA
Oct 18 08:49:48 BKP-ASUS sSMTP[265073]: 354  Go ahead cz16-20020a0564021cb000b00535204ffdb4sm2275216edb.72 - gsmtp
Oct 18 08:49:48 BKP-ASUS sSMTP[265073]: Received: by host.domain.com (sSMTP sendmail emulation); Wed, 18 Oct 2023 08:49:47 +0200
Oct 18 08:49:48 BKP-ASUS sSMTP[265073]: From: "Backup report" <recipient@domain.com>
Oct 18 08:49:48 BKP-ASUS sSMTP[265073]: Date: Wed, 18 Oct 2023 08:49:47 +0200
Oct 18 08:49:48 BKP-ASUS sSMTP[265073]: Subject: Backup report for date 18.10.2023.
Oct 18 08:49:48 BKP-ASUS sSMTP[265073]:
Oct 18 08:49:48 BKP-ASUS sSMTP[265073]: Date 18.10.2023.
Oct 18 08:49:48 BKP-ASUS sSMTP[265073]:
Oct 18 08:49:48 BKP-ASUS sSMTP[265073]: Starting daily at 22.00h
Oct 18 08:49:48 BKP-ASUS sSMTP[265073]:
Oct 18 08:49:48 BKP-ASUS sSMTP[265073]: Starting time is 08:43
Oct 18 08:49:48 BKP-ASUS sSMTP[265073]:
Oct 18 08:49:48 BKP-ASUS sSMTP[265073]: Ending time is je 08:49
Oct 18 08:49:48 BKP-ASUS sSMTP[265073]:
Oct 18 08:49:48 BKP-ASUS sSMTP[265073]: Total copied size is 736M#011/backup/test/
Oct 18 08:49:48 BKP-ASUS sSMTP[265073]:
Oct 18 08:49:48 BKP-ASUS sSMTP[265073]: Copied 412 files
Oct 18 08:49:48 BKP-ASUS sSMTP[265073]:
Oct 18 08:49:49 BKP-ASUS sSMTP[265073]: .
Oct 18 08:49:49 BKP-ASUS sSMTP[265073]: 250 2.0.0 OK  1697611789 cz16-20020a0564021cb000b00535204ffdb4sm2275216edb.72 - gsmtp
Oct 18 08:49:49 BKP-ASUS sSMTP[265073]: QUIT
Oct 18 08:49:49 BKP-ASUS sSMTP[265073]: 221 2.0.0 closing connection 
cz16-20020a0564021cb000b00535204ffdb4sm2275216edb.72 - gsmtp
Oct 18 08:49:49 BKP-ASUS sSMTP[265073]: Sent mail for recipient@domain.com (221 2.0.0 closing connection cz16-20020a0564021cb000b00535204ffdb4sm2275216edb.72 - gsmtp) uid=0 username=r>

But if I cron execute the script, this is what I found in log: (shortened to important part I hope):

Oct 18 04:15:26 BKP-ASUS sSMTP[264166]: 235 2.7.0 Accepted
Oct 18 04:15:26 BKP-ASUS sSMTP[264166]: MAIL FROM:<root@domain.com>
Oct 18 04:15:26 BKP-ASUS sSMTP[264166]: 250 2.1.0 OK g5-20020a1709067c4500b009ad8084e08asm690857ejp.0 - gsmtp
Oct 18 04:15:26 BKP-ASUS sSMTP[264166]: RCPT TO:<recipient@domain.com>
Oct 18 04:15:26 BKP-ASUS sSMTP[264166]: 250 2.1.5 OK g5-20020a1709067c4500b009ad8084e08asm690857ejp.0 - gsmtp
Oct 18 04:15:26 BKP-ASUS sSMTP[264166]: DATA

Any idea why it acts differently with cron?

How to make crontab email me with output?, should take care of sender/recipient of mail. — Luuk, Oct 18 '23 at 11:03
Does this answer your question? How to make crontab email me with output? — Artur Meinild, Oct 18 '23 at 11:06
You could also consider using a 3rd party app to send mail, like sendemail, which allows to specify both receiver and sender on the command line. — Artur Meinild, Oct 18 '23 at 11:07
ssmtp was easier to setup with google hosted mail and it works fine when run manually. If nothing helps, i will switch to another app. So far i hope to find answer to this problem — Marxer, Oct 18 '23 at 11:38
sendemail will use the sendmail/ssmtp command from sSMTP to actually send the mail. It's just a more user-friendly frontend to the sendmail command. I use sSMTP myself on my RasPi with no issues at all, but I also use sendemail as a frontend. — Artur Meinild, Oct 18 '23 at 11:56
I will try to find how to set sendemail and test. So far i did not see how to copy log file content as message body but i guess that it can be done — Marxer, Oct 18 '23 at 13:45

score 0 · Answer 1 · answered Oct 23 '23 at 05:55

In the end, it wasn't as it looks like ... it was not an sSMTP question, it was bash problem. I replaced "#!/bin/bash" with "#!/usr/bin/env bash" and added another line with PATH and now it works as expected! Thanks to everyone who sent the ideas for help.

sSMTP is behaving strangely

1 Answers1