Skip to main content
Set up sending mail via sSMTP on Linux
Last update:

Set up sending mail via sSMTP on Linux

For your information

This is an instruction for configuring mailings via the Selectel mail service using the sSMTP utility on a Linux server.

  1. Make sure that you have enabled the mail service for the domain and the domain has received the status `Verified'. The connected domains and their statuses can be viewed in the [control panel](https://my.selectel.ru/ses /) in the section Mail service → resource page → tab Information → block Linked domains.

  2. Connect to the server in the Selectel infrastructure from which you plan to send mailings:

    Connect to the server via SSH or via KVM console.

  3. Install sSMTP:

    sudo apt update
    sudo apt install ssmtp

  4. Install the auxiliary utility mailx to send mail:

    sudo apt install mailutils

  5. Install the nano:

    sudo apt install nano

  6. Open the configuration file ssmtp.conf:

    nano /etc/ssmtp/ssmtp.conf

  7. Change the contents of the file:

    mailhub=smtp.mail.selcloud.ru:<port>
    AuthUser=<login>
    AuthPass=<password>
    AuthMethod=LOGIN
    rewriteDomain=<example.com>
    hostname=smtp.mail.selcloud.ru
    FromLineOverride=No
    UseSTARTTLS=Yes
    UseTLS=Yes
    # If <port>=1126, then UseTLS=No
    TLS_CA_File=/etc/ssl/certs/ca-certificates.crt

    Specify:

    • <port> — port:

      • 1126 — if you need to establish a no SSL / STARTTLS connection;
      • 1127 — if you need to establish a TLS (SSL) connection.

    • <login> — login, you can view it in the [control panel](https://my.selectel.ru/ses /) in the Mail service section → the page of the resource to which the domain has been added → the Information tab;

    • <password> — the password can be viewed in the [control panel](https://my.selectel.ru/ses /) in the Mail service section → the page of the resource to which the domain has been added → the Information tab;

    • <example.com > is the domain from which you want to send mailings.

  8. Close the file (Ctrl+X) and save the changes (Y).

  9. Open the revaliases configuration file:

    sudo nano /etc/ssmtp/revaliases

  10. Add a line with the address that should be displayed as the sender's address in mailings via the mail service:

    root:<sender_email>:smtp.mail.selcloud.ru:<port>

    Specify:

    • <sender_email> — the sender's address on the domain that you have connected to the mail service, for example, sender@example.com ;
    • <port> is the port that was specified in step 7.

  11. Close the file (Ctrl+X) and save the changes (Y).

  12. Replace the default mail sender with the configured sSMTP:

    sudo mv /usr/sbin/sendmail /usr/sbin/sendmail.orig

  13. Create a symlink to ssmtp instead of `sendmail':

    sudo ln -s /usr/sbin/ssmtp /usr/sbin/sendmail

  14. Send a test newsletter:

    $ echo test | mail -s "testing ssmtp" <recipient_email>

    Specify the <recipient_email> address to which you want to send the test newsletter.