В /etc/mail/mailer.conf создаем алиасы основных сервисов на ssmtp:

В /usr/local/etc/ssmtp/ssmtp.conf изменяем настройки для отправки почты:

#

# /etc/ssmtp.conf -- a config file for sSMTP sendmail.

#

# The person who gets all mail for userids < 1000
# Make this empty to disable rewriting.
root=billing@yarteleservice.ru
www=support@yarteleservice.ru

# The place where the mail goes. The actual machine name is required
# no MX records are consulted. Commonly mailhosts are named mail.domain.com
# The example will fit if you are in domain.com and your mailhub is so named.
mailhub=mail.ewfwece.ru

# Example for SMTP port number 2525
# mailhub=mail.your.domain:2525
# Example for SMTP port number 25 (Standard/RFC)
# mailhub=mail.your.domain        
# Example for SSL encrypted connection
# mailhub=mail.your.domain:465

# Where will the mail seem to come from?
rewriteDomain=erfrvice.ru

# The full hostname
hostname=mydomain

# Set this to never rewrite the "From:" line (unless not given) and to
# use that address in the "from line" of the envelope.
#FromLineOverride=YES

# Use SSL/TLS to send secure messages to server.
#UseTLS=YES

# Use SSL/TLS certificate to authenticate against smtp host.
#UseTLSCert=YES

# Use this RSA certificate.
#TLSCert=/usr/local/etc/ssmtp/ssmtp.pem

# Get enhanced (*really* enhanced) debugging information in the logs
# If you want to have debugging of the config file parsing, move this option
# to the top of the config file and uncomment
Debug=YES

AuthUser=bwerfewr@yfwerfwevice.ru
AuthPass=fuieorf