Using Postfix to send email notifications to gmail or any such email providers causes relay issue (delay in email delivery) since gmail does not allow multiple emails from non-verified emails. I had to figure out delivering email notifications quickly to avoid any delay in response to the alerts generated by Nagios. AWS has a highly reliable email notification service called SES (Simple Email Service) which can be used to deliver such emails. In this blog I will be configuring postfix to relay the emails alerts from Nagios to use the AWS SES for delivering emails to recipients.This blogs assumes you have a working Nagios (hosts and alerts) configured.<\/p>\n
Verify your email which will be used to send emails. You can refer the link http:\/\/docs.aws.amazon.com\/ses\/latest\/DeveloperGuide\/verify-email-addresses.html for detailed steps for email verification on SES.<\/p>\n
By default SES requires email verification for both sender and receiver email addresses. To avoid verification for the email addresses of recipients a request has to be generated on AWS Support for moving the your SES instance out of the sandbox into production. For detailed steps check the links below:<\/p>\n
http:\/\/docs.aws.amazon.com\/ses\/latest\/DeveloperGuide\/request-production-access.html<\/a> Configure your Postfix setup to work as relay. On Ubuntu it can be done using following command. [js] smtp_sasl_auth_enable = yes Enter below details in \/etc\/postfix\/sasl_passwd ( Create if file does not exist ):<\/p>\n For the username, password, accessid and accesskey you will have to generate a user name and password for the SES. To generate the username and password follow the below steps:-<\/p>\n Download the credentials files. The credential files have your accessid and accesskey \u00a0which will be used as username and password.<\/p>\n [js] The configuration is complete. To test your setup try sending a test mail. [js]Example:<\/p>\n # ‘notify-host-by-email’ command definition<\/p>\n define command{<\/p>\n command_name \u00a0\u00a0\u00a0notify-host-by-email<\/p>\n command_line \u00a0\u00a0\u00a0\/usr\/bin\/printf "%b" "***** Nagios *****\\n\\nNotification Type: $NOTIFICATIONTYPE$\\nHost: $HOSTNAME$\\nState: $HOSTSTATE$\\nAddress: $HOSTADDRESS$\\nInfo: $HOSTOUTPUT$\\n\\nDate\/Time: $LONGDATETIME$\\n" | \/usr\/bin\/mail -s "** $NOTIFICATIONTYPE$ Host Alert: $HOSTNAME$ is $HOSTSTATE$ **" $CONTACTEMAIL$ -r sender@example.com<\/p>\n } Restart Nagios : Configuration is complete. Try sending a custom notification via Nagios to test.<\/p>\n","protected":false},"excerpt":{"rendered":" Introduction Using Postfix to send email notifications to gmail or any such email providers causes relay issue (delay in email delivery) since gmail does not allow multiple emails from non-verified emails. I had to figure out delivering email notifications quickly to avoid any delay in response to the alerts generated by Nagios. AWS has a […]<\/p>\n","protected":false},"author":563,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"iawp_total_views":147},"categories":[1],"tags":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/posts\/28605"}],"collection":[{"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/users\/563"}],"replies":[{"embeddable":true,"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/comments?post=28605"}],"version-history":[{"count":0,"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/posts\/28605\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/media?parent=28605"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/categories?post=28605"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/tags?post=28605"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\n– SES Email Sending Limits
\n(<\/i>http:\/\/docs.aws.amazon.com\/ses\/latest\/DeveloperGuide\/limits.html<\/i><\/a>)<\/i>
\n– Increasing SES Sending Limits
\n(<\/i>http:\/\/docs.aws.amazon.com\/ses\/latest\/DeveloperGuide\/increase-sending-limits.html<\/i><\/a>)<\/i><\/p>\n2. Configuring Postfix<\/b><\/h3>\n
dpkg-reconfigure postfix<\/code> On prompting while reconfigure:<\/p>\n\n
\nsmtp_sasl_security_options = noanonymous
\nsmtp_sasl_password_maps = hash:\/etc\/postfix\/sasl_passwd
\nsmtp_use_tls = yes
\nsmtp_tls_security_level = encrypt
\nsmtp_tls_note_starttls_offer = yes
\nsmtp_tls_CAfile = \/etc\/ssl\/certs\/ca-certificates.crt[\/js]<\/p>\n**Your AWS SES SMTP host **:25 accessid:accesskey<\/code><\/p>\n\n
\n
\nsudo chown root:root \/etc\/postfix\/sasl_passwd
\nsudo chmod 0600 \/etc\/postfix\/sasl_passwd
\nsudo postmap hash:\/etc\/postfix\/sasl_passwd
\nsudo chown root:root \/etc\/postfix\/sasl_passwd.db
\nsudo chmod 0600 \/etc\/postfix\/sasl_passwd.db
\nsudo postconf -e ‘smtp_tls_CAfile = \/etc\/ssl\/certs\/ca-certificates.crt’
\nservice postfix restart
\n[\/js]<\/p>\n
\necho test | mail -s \"test message\" -a \"From: sender@example\" recepient@example.com<\/code><\/p>\n**If the email fails please check mail log (tailf \/var\/log\/mail.log)<\/i>. If the mail logs shows verification error please check the email ids being used. Both sender and receiver email id should be verified on SES before testing.<\/address>\n3. Configuring Nagios<\/b><\/h3>\n
\n
\n[\/js]<\/p>\n
\nservice nagios restart<\/code><\/p>\n