Unable to send mail with mailx

Could someone kindly assist with this error?:

mailx -s "test message" recipient@gmail.com Cc: This is a test message
cannot send message: Process exited with a non-zero status

I’m getting this when attempting to use mailx from the command-line.

My best advice to you is to actually use s-nail for this purpose which requires a lot less fussing around than the various versions of mailx / bsd-mailx / heirloom-mailx etc etc available under Ubuntu. In particular s-nail can send directly to external SMTP servers (such as Gmail) without the added complexity of applications such as Postfix.

s-nail can be installed as follows:

sudo apt-get install s-nail

You then need to create a configuration file and set permissions appropriately:

touch ~/.mailrc
chmod 0600 ~/.mailrc

Open this file with your favorite text editor and paste the following information into it. Note the sections that I have mostly marked with ‘xxxxx’ where you will need to add your own details (usually username and password):

# Setting mailx version v14.9.15 for gmail   #

# Testing syntax:
# echo "Testing, Testing, Testing" | s-nail -s "My test..." xxxx@gmail.com

# Use v15.0 compatibility mode
set v15-compat

# See the whole process, especially for troubleshooting:
set verbose

# Essential setting: select allowed character sets
set sendcharsets=utf-8,iso-8859-1
# and reply in the same charset used by sender:
set reply-in-same-charset

# Default directory where we act in (relative to $HOME)
set folder=mail

# My actual address obfuscated here:
set from="xxxxxxxx@gmail.com"

# Request strict TLL transport layer security checks
set tls-verify=strict
set tls-ca-file=/etc/ssl/certs/ca-certificates.crt
set tls-ca-no-defaults
set smtp-use-starttls
set smtp-auth=login

# When sending messages, wait until the Mail-Transfer-Agent finishes.
# Only like this you will be able to see errors reported through the
# exit status of the MTA (including the built-in SMTP one)!
set sendwait

# And of course put your own gmail username and
# App Password here in the obvious places:

set mta=smtps://username:password@smtp.gmail.com:465

I have set this up on my Ubuntu 20.04 system, and it works flawlessly. See below where I have run the suggested test email (note I have munged the test email address):

$ echo "Testing, Testing, Testing" | s-nail -s "My test..." xxxxx@gmail.com
s-nail: P(seudo)R(andom)N(umber)G(enerator): *TLS RAND_*
s-nail: Resolving host smtp.gmail.com:465 ... done
s-nail: Connecting to ...  connected.
s-nail:  Certificate depth 2 
s-nail:   subject = /OU=GlobalSign Root CA - R2/O=GlobalSign/CN=GlobalSign
s-nail:   notBefore = Dec 15 08:00:00 2006 GMT
s-nail:   notAfter = Dec 15 08:00:00 2021 GMT
s-nail:   issuer = /OU=GlobalSign Root CA - R2/O=GlobalSign/CN=GlobalSign
s-nail:  Certificate depth 1 
s-nail:   subject = /C=US/O=Google Trust Services/CN=GTS CA 1O1
s-nail:   notBefore = Jun 15 00:00:42 2017 GMT
s-nail:   notAfter = Dec 15 00:00:42 2021 GMT
s-nail:   issuer = /OU=GlobalSign Root CA - R2/O=GlobalSign/CN=GlobalSign
s-nail:  Certificate depth 0 
s-nail:   subject = /C=US/ST=California/L=Mountain View/O=Google LLC/CN=smtp.gmail.com
s-nail:   notBefore = Nov  3 07:37:59 2020 GMT
s-nail:   notAfter = Jan 26 07:37:59 2021 GMT
s-nail:   issuer = /C=US/O=Google Trust Services/CN=GTS CA 1O1
s-nail: Comparing subject_alt_name: need<smtp.gmail.com> is<smtp.gmail.com>
s-nail: TLS certificate ok
s-nail: TLS BLAKE2s256 fingerprint: 0C:F8:DA:33:CE:15:EA:7F:F6:8B:28:C1:95:33:A0:1D:01:B7:F3:D8:E2:7B:29:42:70:D6:4B:6A:6D:16:8A:CF
s-nail: TLS connection using TLSv1.3 / TLS_AES_256_GCM_SHA384

Hopefully this will work on your Ubuntu 20.04 system as well!


  1. App Password: In modern times you will need to create an App Password with Google for s-nail to access Gmail successfully: https://support.google.com/accounts/answer/185833
  2. Symlinks: Most Linux distros will actually symlink s-nail to mailx so the command mailx will call s-nail but this does not appear to be the case under Ubuntu 20.04. Doubtless, this could be done manually.
Answered By: andrew.46