Ubuntu – How to change default FROM address for mail command using sSMTP


I have installed:

  • sudo apt-get install ssmtp
  • sudo apt-get install mailutils

When I use command:

echo "something" | mail -s "testing email" email@example.com

The generated email have From field set to something like this:

From: "Username" <username@local.domain.internal>

Is there a config file or something, where I can change this FROM default address?

Note, that changing the TO field is easy, as explained here: How to get ssmtp to map local user to email address for the To: field, but I need to change the default FROM field.

Edit: I also need to change FROM address for sendmail emulation. In my case, the Cron sets FROM: root and TO: root, that I would like to change to normal email address.

Best Answer

There are a couple of settings in ssmtp that can be manipulated to allow a change in the 'From' field of emails:

  1. There is a setting within /etc/ssmtp/ssmtp.conf. By default the system selects the 'From' address but this can be altered by unchecking the FromLineOverride line:

    # Are users allowed to set their own From: address?
    # YES - Allow the user to specify their own From: address
    # NO - Use the system generated From: address

    By 'unchecking' I mean remove the hash mark at the beginning of that particular line.

  2. There can be settings within /etc/ssmtp/revaliases to allow a specific 'From' line from each user. The example given in revaliases is reasonably unhelpful:

    # Example: root:your_login@your.domain:mailhub.your.domain[:port]
    # where [:port] is an optional port number that defaults to 25.

    But the man pages gives a much more explicit example:

    A reverse  alias  gives  the From: address placed on a user's outgoing
    messages and (optionally) the  mailhub  these  messages  will  be  sent
    through. Example:
    Messages  root  sends  will be identified as from jdoe@isp.com and sent
    through mail.isp.com.

I personally do not use ssmtp instead I use msmtp where the syntax for altering the 'From' field is a lot simpler and can be contained in the file $HOME/.msmtprc:

from my.email.address@myisp.com

which is a lot easier...


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